hydraulic & hydrology study report peshawar tortham

HYDRAULIC & HYDROLOGY STUDY REPORT

for

Peshawar Torkham Motorway

CONSULTANCY SERVICES

PERTAINING TO FEASIBILITY STUDY

AND PRELIMINARY DESIGN OF

PESHAWAR - KABUL MOTORWAY


Peshawar Tortham Motorway- Section I

Submitted to: National Highway Authority

July2017

Submitted by:

Associated Consultancy Centre (Pvt.) Ltd. (ACC) in association

with SAMBO Engineering Co. Ltd. (South Korea),

ACE-TES Lahore & Assign International


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TABLE OF CONTENTS

Summary ................................................................................................................... v

CHAPTER-1 ................................................................................................................ 1

BACKGROUND .......................................................................................................... 1

1.1 Peshawer Tortham- Section I ........................................................................... 2

CHAPTER-2 ............................................................................................................... 3

OBJECTIVE AND SCOPE OF STUDY ............................................................................ 3

CHAPTER-3 ............................................................................................................... 4

DESCRIPTION OF STUDY AREA ................................................................................ 4

CHAPTER-4 ............................................................................................................... 7

HYDROLOGICAL INVESTIGATION ............................................................................. 7

4.1 General ........................................................................................................... 7

4.2 Climatic Characteristic Analysis ...................................................................... 7

4.3 Rainfall Frequency Analysis .......................................................................... 10

4.4 Rainfall-Runoff Method ................................................................................ 14

CHAPTER-5 .............................................................................................................. 15

HYDRAULIC INVESTIGATION .................................................................................. 15

5.1 Hydraulic Analysis for Major Streams and Nullahs ....................................... 15

5.2 Hydraulic Analysis for Cross-Drainage Structures/ Culverts ......................... 20

5.3 Hydraulic Design Analysis for Side Channels ................................................. 29

CHAPTER-6 ............................................................................................................. 32

FINDINGS & RECOMMENDATIONS .......................................................................... 32

References ................................................................................................................ 33

ANNEXURES............................................................................................................. 34

Annexure A: Historical Climatic Data for Peshawar ................................................ 35

Annexure-B: Catchments Delineation of Major Streams/ Nullahs ............................ 39

Annexure-C: Hydrologic and Hydraulic Parameters relating Bridges over Major Streams/ Nullahs ..................................................................................................... 50

Annexure-D: Hydraulic Outputs of Major Streams/ Nullahs .................................... 53

Annexure-E: Scour Depth Estimation by Lacey Regime Theory .............................. 64


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LIST OF FIGURES

Figure 1: Location of Peshawar-Torkhum Road ........... Error! Bookmark not defined.

Figure 2: Geo-referenced location of proposed alignment under study ..................... 3

Figure 3: Peshawar-Torkhum Proposed Alignment Location Map ........................... 4

Figure 4: Average Temperature Pattern ................................................................... 8

Figure 5: Average Rainfall Patter .............................................................................. 8

Figure 6: Long Term Maximum Temperature Pattern in Study Area ........................ 9

Figure 7: Long Term Minimum Temperature Pattern in Study Area ......................... 9

Figure 8: Long Term Annual Rainfall Pattern in Study Area ................................... 10

Figure 9: Hydrology of Study Alignment .................................................................. 11

Figure 10: HEC-SSP Computer Modei ....................................................................... 12

Figure 11: Rainfall Frequency Curve for Study Alignment (Gumbel) ........................ 12

Figure 12: Rainfall Frequency Curve for Study Alignment (GEV) ..............................13

Figure 13: Computer Model HEC-HMS ...................................................................... 14

Figure 14: Scheme of runoff generation due to rainfall ............................................ 29

Figure 15: Scheme of protective measures for the road ............................................ 30

Figure 16: Schematic of Drop Structure along embankment .....................................31


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LIST OF TABLES

Table 1: Rainfall Estimates of Standard Return Periods (in mm) ..............................13

Table 2: Flood Characteristics through the proposed bridges along alignment ......... 17

Table 3: Proposed X- Drainage Structures ................................................................ 21

Table 4: Schedule of Proposed X-Drainage Structures .............................................. 22


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Summary

The trade via Afghanistan towards Central Asian countries and from Arabian sea has been centuries old activity through road connectivity. With the passage of time, the traffic has increased tremendously, exerting pressure on existing road infrastructure, arising need for an improved road infrastructure from Peshwar to Torkham to meet the expanding communication needs, especially after CPEC (China-Pakistan Economic Corridor) initiative. The current hydrological investigation is carried out to study the hydrological regime and allied impacts for safe development and operation of Peshawar-Torkham Expressway (approx 47 km) in the northern part of the Khyber Pakhtunkhwa province of Pakistan.

The Peshawar-Torkham proposed alignment falls in the areas mainly in terrains with barren and rugged mountains where several small streams and nullahs cross the alignment. The area falls in the climate mostly under semiarid Mediterranean influence and less monsoon effects with annual total around 400 mm. The average temperature in summer varies from 18 to 40 oC whereas the winter average temperatures range from 2 to 25 oC. However, the extreme temperatures could be below 0 oC in winters and more than 40 oC in summers. The long term temperature analysis (1974 to 2015) does not present any major deviation in the temperatures both in summer and winters. Whereas long term rainfall pattern shows an increasing trend in annual totals due to the fact that monsoon rains are moving upward towards northern parts of the country. However, the study alignment moves further upward, where such impact would not be that significant as Mediterranean disturbances having more influence in upper parts of the alignment.

Based on the rainfall and runoff analysis in connection with the topography of the area, there have been proposed 22 bridges to safely pass the runoff generated from the upstream and adjoining areas. The design parameters for the bridges have been provided based on hydraulic analysis under the study in order to pass the standard floods safely (100-year). For bridges over major streams and nullahs, scour depth analysis have also been provided. Similarly, for overland flow and minor natural channels, 132 culverts have been proposed (including modification of 11 existing ones) for which design parameters are also provided to safely pass standard flood of 50-year recurrence interval.

The road is located in the range where topography varies from mild to steep. The road may come mostly under the effect of direct flow from the hills in the form of torrents as flash flood; also carrying mud/boulders on its way. To avoid this, drainage channels along the road on hill sides connected to the nearest x-culverts may be provided to protect the road, for which design has also been proposed. The overland flow from the road itself may be passed through road-side drop structure and connected to corresponding culvert or existing conveyance system (watercourse or drain). In the design of culverts, there has been kept cushion for such overland flow from the road itself, giving 20% (0.2 to 0.3 m) freeboard for all culverts.


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CHAPTER-1 BACKGROUND The subject road is connecting Peshawar with Kabul through Torkham and Jalalabad.

Peshawar is the capital of Khyber Pakhtunkhwa and the administrative centre and

economic hub for the Federally Administered Tribal Areas of Pakistan. Peshawar is

situated in a large valley near the eastern end of the Khyber Pass, close to the Pak

Afghan border. Known as “City on the Frontier”, Peshawar’s strategic location on the

cross roads of Central Asia and South Asia has made it one of the most culturally vibrant

and lively cities in the greater region. Peshawar is connected to Motorway system of

Pakistan through Motorway M-1.

Peshawar Northern Bypass having a definition of 4-lane dived Expressway provides link between Motorway M-1 and Start Point of Peshawar – Kabul Motorway. Total Length of the existing road from Peshawar (Hayatabad) to Kabul (Abdul Haq Square) is approximately 281 KM (Project alignment between Peshawar and Kabul is shown in Figure 1). The project is divided into following three sections:

Table 1: Project Sections

Sr. No. Section Name of Section Length (KM)

1 Section - I Peshawar – Torkham (Pakistan) 50

2 Section – II Torkham – Jalalabad (Afghanistan) 76

3 Section - III Jalalabad –Kabul (Afghanistan) 155

Figure 1: Existing Alignment of Peshawar-Kabul Project

From Peshawar to Torkham, the terrain is very difficult in some reaches where the alignment mostly follows valleys and hill slopes. Although the design is completed by


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NHA for the section between Peshawar and Torkham but it is envisaged that the consultant shall provide further value addition and improvement. From Torkham to Jalalabad the existing 2-lane is being upgraded to 4-lane by FWO. The work is held up due to various reasons, it shall now be redesigned/upgraded to Motorway Standard. The distance from Torkham to Jalalabad is 76 Km. From Jalalabad to Kabul using Kabul – Nangarhar Highway the existing road measures 139 km. The terrain is mountainous with hard rock and steep vertical slopes. Especially about 50 km section after Sarobi. It is envisaged that total Motorway length shall be around 265 Km1. Tunnels exist in Afghanistan section of the Highway.

1.1 Peshawar- Torkham, Section I

In the first phase, the Consultant has been advised to carry out feasibility study and

preliminary design of Peshawar-Torkham Section. The Consultant have studied various

alignment alternates in order to achieve stipulated motorway standards. Options of

provision of tunnels in mountainous reach was also investigated. Final proposed

Motorway alignment from Peshawar-Torkham is shown in Figure 2.

Figure 2: Project Alignment of Peshawar-Torkham (Section-I)

On completion of alignment study, requirement of cross drainage structures has been

investigated and preliminary design of structures has been carried out. The subject

report has been prepared as the "Hydrology & Hydraulic Study Report" for Peshawar-

Torkham Section as required by the deliverables of the TOR of the project.

1As per TOR the length is 281 km.


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CHAPTER-2 OBJECTIVE AND SCOPE OF STUDY

The main objective of the study is to carry out hydrological investigations with

reference to the proposed alignment from Peshawar to Torkham in Khyber

Pakhtunkhwa province of Pakistan, expanding over a length of about 47 km. The

specific scope of the study however is:

1. To carry out hydrological investigation with the analysis of rainfall and

flood records supplemented by detailed field investigations for

development of new road alignment and providing required

2. Analyze and propose required cross-drainage structures for the safe

development and operation of the proposed alignment such as bridges,

culverts, support structures etc. against standard flood conditions (100

years for bridges and 50 years for culverts)

3. Submit recommendations based upon concise analysis supported by field

data for embankment, crossing/ drainage bridges, culverts etc. along the

proposed alignment.

The flyovers and other road crossing bridges are not discussed being not scope

of study. The geo-referenced location of the subject road is shown in Figure 2.

Figure 3: Geo-referenced location of proposed alignment under study


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CHAPTER-3 DESCRIPTION OF STUDY AREA

The proposed alignment from

Peshawar to Torkham would be a

major road of about 47 km. This

existing single carriageway (N-5)

provides access from Peshawar to

Torkham. However, the expanding

traffic load demands an expressway

for smooth transportation of goods to

and from Afghanistan and onwards.

The proposed 4-lanes dual alignment

starts from Peshawar near Jamrud and

approx 4 km from Peshawar Ring Road (Figure 3). It runs parallel to the existing

N-5 whereas the distance apart varies from 0.5 to 2 km with terrain varying in

elevation. The proposed alignment crosses several small and medium streams

and nullahs (perennial/ non-perennial) where crossing bridges and drainage

structures would be required. Such considerations would be of importance to be

taken care for the safety of the road.

Figure 4: Peshawar-Torkham Proposed Alignment Location Map

Proposed Alignment


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The climate of the area in which the new alignment falls is semiarid subtropical

continental highland type. The mean annual rainfall is approximately 450 mm, of

which 200 mm falls in March and April, with warm summers and cool winters. The

area falls out of the monsoon belt where the major portion of rainfalls occurs due

to western disturbances. The average daily maximum temperature of the hottest

month is 36°C and the average daily minimum of the coldest is -0.5°C.

The study alignment mainly falls in the Khyber Agency – Federally Administered

Tribal Areas. This the geological region of Pre-aravallis, metamorphic in general

including Precambrian and younger intrusions. The massive grey limestone with

sand and clay beds that makes up the Carboniferous Khyber Formation and the

slate, phyllites and schists with minor limestone and quartzite beds of the

Ordovician-Silurian Landi Kotal Formation in the eastern part of the Khyber

Agency. Mesozoic sediments occur in the western part of the Khyber Agency

(Kruseman and Naqvi, 1988). Near Warsak on the boundary with the Peshawar

Vale is a granite intrusion (Shah et al., 1980). In the western part Jurassic

limestone has been found (Meissner at al.,1975).

The Khyber Agency is mountainous without any well developed alluvial plain.

According to the available information, approximately 20 test-and tube wells have

been drilled in different valleys. The lithological data on two boreholes in the

Jamrud – Landi Kotal area indicate an ill-sorted mixture of clay and gravels,

probably with low transmissivity values. The depth to water level is quite large

(more than 30 m). If these boreholes are representative of the whole area, then

the groundwater development is not viable (Kruseman and Naqvi, 1988).

The land use is generally mild hilly terrain with barren and rugged mountains,

without a well-developed alluvial plain. However, the green valleys are also seen.

But it also has some beautiful valleys with plain cultivable lands. The elevation

varies from about 396 to 1050 along the alignment however, the hills are higher

than these. The soils are derived mainly from the local weathering of bedrock,

deposited by streams and rivers, though loess also occurs to some extent.

Landforms in the area are varied and include piedmont, plains, valleys, gravel

fans, rough broken land and gullied land. Level areas are loamy, while lowlands

are slightly to strongly calcareous. The content of organic matter and available

phosphorus is very low.


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The population is scattered in the area with minimal road and other civil facilities.

Due to recent insurgencies in the FATA areas, it is also badly affected due to

refugees affecting the natural land use/ land cover of the area. The development

of new highway will play a major role in the development of this under-privileged

area as well as help further developing the trade.


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CHAPTER-4 HYDROLOGICAL INVESTIGATION

4.1 General

The hydrological investigation under the current study has been carried out to

analyze the climate cum flow regime in connection with the development of

Peshawar to Torkham highway extending over a stretch of 46 about. For such

development it is necessary to take all necessary deign and protection measures

for safe operation of the road after its development for its service life. The design

considerations and measures could be: appropriate embankment/ alignment,

cross drainage structures including bridges, culverts and drops structures to

safeguard against possible rainfall/ flooding or surface runoff, and inundation

impacts. For such type of structures, the recurrence interval is generally adopted

as 100 year for large bridges and 50 year for small structures and culverts

(Mutreja, 1990).

The land use layout of proposed alignment is such that it mainly passes through

mountainous terrains where the runoff flux due to rainfalls could be either from

the hills along the road or the natural steams or nullahs crossing the alignment.

This section therefore focuses to estimate the runoff flux to the road alignment so

that the protective measures and cross-drainage structures could be proposed to

safeguard the alignment. For this purpose, there could be two different

approaches or sometimes the combination of both to estimate the runoff

magnitude of standard return periods viz. i) Discharge frequency analysis using

observed data, and ii) well practiced and acceptable rainfall-runoff methods

making use of observed rainfall which is mostly available along with physical

characteristics of the catchment areas from where the runoff is generated. Such

hydrological analyses have been presented hereafter.

4.2 Climatic Characteristic Analysis

The study alignment falls in the arid to semi-arid region. In order to analyze the

climatic characteristics of area, it was explored to find weather data source or

climatic station in the area exit in such area. The Peshawar is the only climatic

station where Pakistan Meteorological Department has long term rainfall and

temperature record which has been obtained accordingly and analyzed under the

current study from 1974 to 2015 (41 years). The average temperature pattern

shows that the summer temperatures vary from 18 to 40 oC whereas the winter

average temperatures range from 2 to 25 oC (Figure 4). However, the extreme

temperatures could be below 0 oC in winters and more than 40 oC in summers.


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The rainfall is due to more Mediterranean influence and less monsoon effects

with annual total around 400 mm (Figure 5).

Figure 5: Average Temperature Pattern

Figure 6: Average Rainfall Pattern

The temperature extremes were analyzed for study area as it plays significant

role in the material selection. For this purpose, long term annual maximum and

minimum temperatures were analyzed from the observed temperature data and

the results are shown in Figure 6. The general trend shows that during summer

the maximum temperature is higher than 45 oC with extremes of 48 oC. However,


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looking at long term averages, no significant rise in maximum temperature is

observed (1974 to 2015). However, for winter temperatures, if we ignore the

outlier of year 2012 (15 oC), the average trend almost remains the same over the

period of 1974 to 2015.

Figure 7: Long Term Maximum Temperature Pattern in Study Area

Figure 8: Long Term Minimum Temperature Pattern in Study Area

Whereas long term rainfall pattern shows an increasing trend in annual totals

(Figure 8). This is due to the fact that monsoon rains are moving upward towards


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northern parts of the country – the unprecedented flood of 2010 and thereafter.

However, the study alignment moves further upward, where such impact would

not be that significant as Mediterranean disturbances having more influence in

upper parts of the alignment.

Figure 9: Long Term Annual Rainfall Pattern in Study Area

4.3 Rainfall Frequency Analysis

The alignment falls in the area where there are several small and medium

streams crossing the proposed alignment (Figure 9). The frequency analysis of

historical floods records if available plays significant role in hydrological studies to

analyze the flooding threat from nearby or crossing rivers/ streams to a point of

interest in terms of flood magnitude, its inundation effects and flood elevation.

This also allows deciding viable protection measures and suggesting x-drainage

structures. There are 22 locations where x- drainage bridges are proposed and

132 sites where culverts are identified. However, there is neither possible

gauging for discharge measurement nor any long term discharge record exists in

the area.


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Figure 10: Hydrology of Study Alignment

Alternatively, long term rainfall extreme events play significant role to estimate

the standard rainfalls (100, 50, or 25 years). These standard rainfalls would be

then used to convert into runoff using standard rainfall-runoff methods, such as

SCS Synthetic Unit Hydrograph method. Therefore, under the current study, such

approach was followed. For the estimation of rainfall of standard recurrence

intervals, Generalized Extreme Value Distribution (GEV) is mostly used. In this

case, it is Type-I i.e. Gumbel Distribution for extreme events (a two parametric

distribution) which is well suited for most Pakistani catchments especially relating

frequency analysis. The frequency analysis of observed annual maximum

rainfalls (1974 to 2015) was carried out using widely accepted HEC-SSP

software developed by US Army Corps of Engineers (Figure 10). This ensures

more rigorous analysis for better decision making. The estimated rainfall

frequency curves are shown in Figure 11 (Gumbel) and Figure 12 (GEV).


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Figure 11: HEC-SSP Computer Model

Figure 12: Rainfall Frequency Curve for Study Alignment (Gumbel)

Probability

0.9999 0.999 0.99 0.9 0.5 0.2 0.1 0.02 0.005 0.001 0.0001

Return Period

1.0 1.1 2 5 10 50 200 1000 10000

An

nu

all

Ma

xim

um

Ra

infa

ll (1

97

4-2

01

5)

in m

m

10.0

100.0

1000.0

General Frequency Analytical Plot for Rainfall at Peshawar

Computed Curve Expected Probability Curve

5 Percent Confidence Limit 95 Percent Confidence Limit

Observed Events (Weibull plotting positions) High Outlier


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Figure 13: Rainfall Frequency Curve for Study Alignment (GEV)

The rainfall estimates for standard return periods of 50-year and 100-year are

drawn in Table 1, which indicate difference in standard rainfall estimates as 14%

to 21% between Gumbel and GEV distributions. However, for rainfall frequency

analysis relating major events, a recent global survey on the distribution of annual

maxima of daily rainfall by Apalexiou and Koutsoyiannis (2012) have provided

that GEV (Log Pearson Type III) distribution is most suitable for large return

periods. Therefore, the maximum estimates were adopted under the current

study and also in the light of increasing rainfall trends in Figure 4.

Table 1: Rainfall Estimates of Standard Return Periods (in mm)

S.No. Distribution 50-Year 100-Year

1 Gumbel 177 204

2 GEV 201 248

Difference 14% 22%

Probability

0.9999 0.999 0.99 0.9 0.5 0.2 0.1 0.02 0.005 0.001 0.0001

Return Period

1.0 1.1 2 5 10 50 200 1000 10000

An

nu

all

Ma

xim

um

Ra

infa

ll (1

97

4-2

01

5)

in m

m

10.0

100.0

1000.0

General Frequency Analytical Plot for Rainfall at Peshawar

Computed Curve Expected Probability Curve

5 Percent Confidence Limit 95 Percent Confidence Limit

Observed Events (Weibull plotting positions) High Outlier


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4.4 Rainfall-Runoff Method

The standard rainfall estimates made in Section 4.3 were converted into runoff of

standard return periods (100 and 50 years) to analyze the behavior of floods in

relation to the alignment either through crossing steams for determining

clearance and size of bridges or suggesting structures like culverts for drainage

purposes. For this, SCS Synthetic Unit Hydrograph method was used to carry out

rainfall-runoff analysis using HEC-HMS Computer Model (Figure 13) to simulate

floods of desired return periods at points of interest along the proposed

alignment. For this purpose, GIS applications were made for estimating the

catchments characteristics (watershed area, main stream length, average slope,

land use etc.) used as input in the model (Annexure-B).

Figure 14: Computer Model HEC-HMS

All such discharge estimates from each identified crossing stream and small

catchments overland flow to the alignment, were studied through hydraulic

analysis presented in the coming sections. This was done in order to see the

impact to the alignment and suggest accordingly the protective measures and

design parameters for necessary drainage structures.


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CHAPTER-5 HYDRAULIC INVESTIGATION

5.1 Hydraulic Analysis for Major Streams and Nullahs

The main objective of this investigation was to analyze the behavior of potential

flood from major streams and nullahs passing the subject Peshawar-Torkham

proposed alignment in order to see the impact of flooding on the alignment and

assess the capacity of required bridges and drainage structures. This would help

suggesting the bridge design, embankment height and/or allied protection

measures. Using the detailed topographic, cross sectional and longitudinal profile

data, it is possible to study the flood behavior/ inundation extent and suggest

measures under given potential flood conditions.

In order to carry out the

hydraulic study, the analysis

was carried out using HEC-

RAS Hydraulic Model

because of its wide range

applicability. The US Army

Corps of Engineers’ River

System (HEC-RAS 5.01)

model allows performing

multi-purpose one and two-

dimensional steady and

unsteady flow river

hydraulics analysis. The

model was applied in the

current study to analyze the

flow profiles of potential

flood (100-year in this case)

along the alignment..

In order to model the potential floods behavior through the proposed 22 bridges

and crossing streams, the following data were provided as input to HEC-RAS

model;

Observed X-sectional data at 100 m intervals from upstream (1.0 km) and

downstream (0.5 km) of the alignment

Existing structures and protections

Average slope of reach


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Magnitude of flood/ discharge (100-year) at the starting point of each study

reach

Manning’s roughness coefficient for natural streams taken as n= 0.025

Known highest flood marks from the physical field conditions for

calibration/validation purposes.

The existing alignment and ground NSL

The model was run simultaneously in calibration/ validation process and the final

outcomes of the modeling results were drawn in Table 2, wherein the finish levels

of the road have been proposed in contrast to the highest flood levels through the

proposed bridges, keeping in view the safety of the proposed highway. The

hydraulic parameters for the bridges over these streams and nullahs are also

given in Annexure-C, whereas the hydraulic model outputs are given in

Annexure-D for further elaboration.

All the bridges have been so proposed to have sufficient capacity as the floods in

these areas also bring lot more mud and boulders along due to bare mountains

and steep slopes. For this purpose, the scour depth calculations have also been

made using Lacey Regime Theory (Lacey, 1946). The conditions of Lacey’s

regime are very rarely achieved and are very difficult to maintain in practice.

However, in rivers and streams only in bank full stage or high flood conditions, it

may be considered to achieve temporary or quasi-regime. The recognition of this

fact can be utilized to deal with the issues concerning scour and floods. The total

scour depth for each proposed bridge is therefore given in Table 2, whereas the

estimations are also provided in Annexure-E. As per general rule, the piling depth

for bridges is taken as double the scour depth.


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Table 2: Flood Characteristics through the proposed bridges along alignment

S.#.

RD/ Location on

Pesh-Torkhum

Road

Structure Type

Location/ Name of stream

Bridge Size

Catchment Area

100-year discharge/ design capacity

Deck Level (top of road)

Highest Flood Level

Total Scour Depth

km Cell x

Span (m) km

2 cumecs cusecs m m m

1 7+060 Bridge Chaura Khwar near

Jamrud 7 x 40 425.31 2356 83119 497.225

481.00 (481.00)

8.02

2 8+650 Bridge Nullah 1 x 30 0.53 12.72 449 542.500 532.780

(532.790) 1.26

3 8+890 Bridge Nullah 1 x 40 0.73 17.50 617 542.500 537.060

(537.060) 1.33

4 9+580 Bridge Nullah 1 x 40 1.41 34 1197 543.86 538.110

(538.110) 1.96

5 21+920 Bridge Khyber Khwar at Ali

Masjid 2 x 40 70.00 341 12016 758.966

753.670

(753.670) 4.21

6 22+560 Bridge Khyber Khwar (RD22+560)

2 x 30 69.80 340 11995 785.351 772.00

(772.00) 3.11


2 x 25 69.60 339 11960 785.63 779.100

(779.10) 3.42


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S.#.

RD/ Location on

Pesh-Torkhum

Road

Structure Type


Bridge Size

Catchment Area



Highest Flood Level

Total Scour Depth

km Cell x

Span (m) km



4 x 30 63.00 307 10831 810.38 803.910

(803.900) 4.07

9 24+700 Bridge Nullah 2 x 35 7.70 92.3 3257 828.000 824.50

(824.50) 1.85


1 x 40 56.00 273 9613 840.540 836.170

(836.17) 3.12

11 25+810 Bridge Chingai Khwar 2 x 20 3.29 79 2780 870.000 867.030

(867.000) 2.59

12 28+700 Bridge Kagga Khwar at

Wali Khel 2 x 30 8.45 145 5113 956.000

953.100

(953.190) 3.17

13 30+460 Bridge Dand Khwar 1 x 25 9.00 154 5449 962.000 958.630

(958.630) 2.98

14 33+000 Bridge Bori Khwar 1 x 20 6.80 117 4117 1006.000 1003.660

(103.660) 2.87

15 33+587 Bridge Sawal Khwar 1 x 20 9.00 154 5449 1017.000 1013.66

(1013.660) 3.05


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S.#.

RD/ Location on

Pesh-Torkhum

Road

Structure Type


Bridge Size

Catchment Area



Highest Flood Level

Total Scour Depth

km Cell x

Span (m) km


16 35+002 Bridge Nullah 1 x 25 1.36 32.8 1158 1024.000 1019.750

(1019.760) 1.93

17 36+410 Bridge Nullah 1 x 40 5.60 96 3390 1041.675 1024.870

(1024.870) 2.60

18 39+680 Bridge Nullah 3 x 30 0.80 19.2 677 958.000 949.130

(949.110) 1.62

19 40+545 Bridge Wuch Tangi 1 x 40 9.75 117 4124 922.9 898.550

(898.560) 2.71

20 43+230 Bridge Nullah 1 x 30 3.20 55 1939 808.000 804.16

(804.160) 2.29

21 45+215 Bridge Nullah 1 x 40 15.00 181 6373 749.726 738.540

(738.570) 2.73

22 46+300 Bridge Giani at Torkham 4 x 25 29.20 350 12349 711.000 708.290 4.25


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5.2 Hydraulic Analysis for Cross-Drainage Structures/ Culverts

On the basis of inundation analysis and cross-drainage needs at the point of

interests along the proposed alignment, it was analyzed to assess the required

design capacity of proposed culverts at 132 locations to safely pass flow of

certain magnitude (50 years return period) to withstand the embankment as well

as smooth operation of the alignment under such standard flood conditions.

All such analysis was carried out using a well established computer model HY-8

Culvert Analysis to determine the design parameters of culvert at each point of

interest. The software has been structured to be self-contained and is mostly

used by roadway design engineers.

HY-8 Culvert Analysis Model

For this purpose, GIS applications were also made for estimating the catchments

characteristics (watershed area, main stream length, average slope, land use

etc.). This was done first estimating the standard runoff from standard rainfalls

(50 years) using HEC-HMS Computer Mode. The standard flow at respective

point of interest was estimated for using as input in the HY-8 Culvert Analysis

Computer Model to estimate viable culvert parameters (shape, number of cells,

width, height, freeboard).


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On the basis of analysis, total 132 box culverts have been proposed including

improvement of 11 existing ones (Table 3). The design parameters are given in

Table 4 providing sufficient design capacity to safely pass the runoff generated

especially from the steep slopes along the road which also bring sediment/

boulders along with due to generally bare mountains. For such purposes, the

sufficient viable capacity of the culverts has been proposed.

Table 3: Proposed X- Drainage Structures

S.No. Structures Nos.

1 New Box culverts 121

2 Modification/ rehabilitation of existing into

Box culverts 11

Total 132


for


22

Table 4: Schedule of Proposed X-Drainage Structures

(Manning’s n=0.020 for concrete culverts; Curve Number for SCS Runoff Estimation CN=75 )

S.# Station Remarks

Culvert Parameters Associated Catchment

Area

Runoff Generated (Qobs)

Design Capacity of Culverts (Q

design)

No. of Cells Span (L)

m Height (H) m

km2 cumecs cumecs

1 0+229 Provide new box culvert 2 3 3 0.115 1.94 11.82


3 1+000 Provide new box culvert 1 2 2.5 0.100 1.69 2.64
















for


23

S.# Station Remarks


Area



design)


m Height (H) m

km2 cumecs cumecs























for


24

S.# Station Remarks


Area



design)


m Height (H) m

km2 cumecs cumecs























for


25

S.# Station Remarks


Area



design)


m Height (H) m

km2 cumecs cumecs














73 23+245 Dismantle existing structure and provide new box culvert

1 3 4 0.224 3.78 8.43


1 3 4 0.256 4.32 8.43

75 23+655

Dismantle existing structure and provide new box culvert

1 3 4 0.120 2.03 8.43



1 2 4 0.070 1.19 4.62

78 24+884


1 3 4 0.144 2.43 8.43


for


26

S.# Station Remarks


Area



design)


m Height (H) m

km2 cumecs cumecs


2 3 2.5 0.158 2.67 9.38


2 3 4 0.523 8.82 16.86



1 3 3 0.120 2.03 5.91


















for


27

S.# Station Remarks


Area



design)


m Height (H) m

km2 cumecs cumecs




102 31+940 Provide new box culvert 1 2 2

0.090 1.52 2.00














1 2 1.5 0.028 0.47 1.39


1 2 1.5 0.038 0.64 1.39


for


28

S.# Station Remarks


Area



design)


m Height (H) m

km2 cumecs cumecs

117 40+005


1 2 1.5 0.053 0.90 1.39





122 42+679 Provide new box culvert 1 2 4












for


29

5.3 Hydraulic Design Analysis for Side Channels

Storm water management of roads should be integrated with management of

surrounding land and development. However, the drainage of runoff from the

along the road and its surface should be so designed to avoid any damage or

ponding to the road surface for safe operation of the highways.

The road is located in the range where topography varies from mild to steep. The

road may come mostly under the effect of direct flow from the hills in the form of

torrents as flash flood (Figure 14). The main threat to the road would be from

such torrents which are flash floods in the form of sheet flow and may damage

the road if no protective measures are adopted to control and their safe passage.

The case would be more critical as the flood water carry mud/boulders on its way.

Figure 15: Scheme of runoff generation due to rainfall

For example an area of 500 m upto 50 m height of hill with 43 mm critical rainfall

(in 15 minutes) may bring about 0.24 cumecs (8.5 cusecs) to the road using

following Rational formula:

Q = C i A (1)

Where

Q = Discharge in cusecs

Road

Slope along the road

NSL

Rainfall

Runoff


for


30

C = Runoff Coefficient (taken 0.80 in present case)

i = Rainfall intensity (inches per hour)

A = Area in acres

So Q = 0.8 x 1.72 x 6.2

= 8.53 cusecs (0.24 cumecs)

To avoid this, drainage channels along the road on hill sides connected to the

x-culverts may be provided to protect the road. Further, reinforced retaining walls

would also be required especially at steep slopes. The scheme along with design

of side channel is shown in Figure 15.

Figure 16: Scheme of protective measures for the road

Adequate cut-off must be provided such that the maximum length of flow path in

the road drainage channel does not exceed up to a reasonable length, preferably

200 m. The cut-off must discharge to a natural watercourse. In the instant case, it

is proposed that drainage may be provided from the sides connecting through

drop structures with proper riprap arrangements (Figure 16) to avoid any rill

development of the embankment. Under the propose alignment, there is at least

one cross-drainage structure at about 300 m apart so the road overland flow may

be diverted to the nearest one through drop structures. And the given proposed

culverts have suffici9ent capacity with 20% freeboard to accommodate such

overland flows.

Road

Slope along the road

NSL Rainfall

Runoff

Proposed side channels 0.8 m

0.5 m

Retaining walls

2:1


for


31

Figure 17: Schematic of Drop Structure along embankment


for


32

CHAPTER-6 FINDINGS & RECOMMENDATIONS

The major findings and recommendations of the study are:

i. The Peshawar-Torkham proposed alignment falls in the areas mainly in terrains with barren and rugged mountains where several small streams and nullahs cross the alignment.

ii. The area falls in the climate mostly under Mediterranean influence and less monsoon effects with annual total around 400 mm. The average temperature in summer varies from 18 to 40 oC whereas the winter average temperatures range from 2 to 25 oC. However, the extreme temperatures could be below 0 oC in winters and more than 40 oC in summers.

iii. The long term temperature analysis (1974 to 2015) does not present any major deviation in the temperatures both in summer and winters. Whereas long term rainfall pattern shows an increasing trend in annual totals due to the fact that monsoon rains are moving upward towards northern parts of the country. However, the study alignment moves further upward, where such impact would not be that significant as Mediterranean disturbances having more influence in upper parts of the alignment.

iv. Based on the rainfall and runoff analysis in connection with the topography of the area, there have been proposed 22 bridges to safely pass the runoff generated from the upstream and adjoining areas. The design parameters for the bridges have been provided based on hydraulic analysis under the study in order to pass the standard floods safely (100-year), besides scour depth analysis.

v. Similarly, for overland flow and minor natural channels, 132 culverts have been proposed (including modification of 11 existing ones) for which design parameters are also provided to safely pass standard flood of 50-year recurrence interval.

vi. The road is located in the range where topography varies from mild to steep. The road may come mostly under the effect of direct flow from the hills in the form of torrents as flash flood; also carrying mud/boulders on its way. To avoid this, drainage channels along the road on hill sides connected to the nearest x-culverts may be provided to protect the road, for which design has also been proposed.

vii. The overland flow from the road itself may be passed through road-side drop structure and connected to corresponding culvert or existing conveyance system (watercourse or drain). In the design of culverts, there has been kept cushion for such overland flow from the road itself, giving 20% (0.2 to 0.3 m) freeboard for all culverts.


for


33

References

Kruseman, G.P. and Naqvi, S.A.H., (1988), Hydrogeology and Groundwater

Resources of the North-West Frontier Province Pakistan, A joint publication of

WAPDA Pakistan and Institute of Applied Geosciences, Delft Netherlands.

1988

Lacey, G. (1946), A general theory of flow-in alluvium. Journal of the

Institution of Civil engineering. London, Vol.27, 16-47, Vol.28, pp. 425-451.

Meissner, C.R., M. Hussain, M.A. Rashid and U.B. Sethi,1975. Geology of the

Parachinar Quadrangle, West Pakistan. US Geol. Survey; Prof. Paper 716-F;

24 pp.

Mutreja K. N. (1990), Applied Hydrology, Tata McGraw-Hill Publishing

Company, Ltd, New Delhi, 1990.

Papalexiou, S.M., and D. Koutsoyiannis (2012), A global survey on the

distribution of annual maxima of daily rainfall: Gumbel or Fréchet?, European

Geosciences Union General Assembly 2012, Geophysical Research

Abstracts, Vol. 14, Vienna, 10563, European Geosciences Union, 2012.

Shah, S.M.I., R.A. Siddiqi, and J.A. Talent, 1980. Geology of the eastern

Khyber Agency, North Western Frontier Province, Pakistan. Records of the

Geol. Survey Pakistan; Vol. 44.


for


34

ANNEXURES


for


35

Annexure A: Historical Climatic Data for Peshawar

Annual Daily Maximum and Total Annual rainfall

Years Daily Maximum Rainfall

(mm) Annual Total Rainfall

(mm)

1974 19.40 190.20

1975 53.50 434.90

1976 102.00 612.16

1977 113.50 452.07

1978 68.50 497.78

1979 54.40 403.97

1980 45.50 372.37

1981 56.00 393.29

1982 40.70 326.36

1983 84.70 710.24

1984 86.80 521.98

1985 62.00 340.81

1986 47.50 416.05

1987 52.40 342.57

1988 44.30 360.90

1989 35.00 251.03

1990 55.00 453.91

1991 62.00 384.42

1992 56.00 579.93

1993 67.00 466.51

1994 51.00 642.52

1995 55.00 618.73

1996 142.00 667.35

1997 30.00 299.54

1998 47.00 569.73

1999 48.00 407.44

2000 33.00 258.89

2001 27.00 263.22

2002 30.00 299.03

2003 65.00 904.73

2004 68.00 453.04

2005 72.00 625.00

2006 56.00 497.50


for


36

Years Daily Maximum Rainfall

(mm) Annual Total Rainfall

(mm)

2007 84.00 575.40

2008 78.00 719.90

2009 187.00 533.00

2010 274.00 839.00

2011 122.10 568.00

2012 88.00 480.00

2013 80.00 551.00

2014 30.00 326.00

2015 65.00


for


37

Daily Annual Maximum and Minimum Temperature

Years Daily Maximum Temperature

(oC)

Daily Minimum Temperature (oC)

1974 46.00 0.00

1975 47.00 0.00

1976 46.00 0.00

1977 45.00 1.00

1978 47.00 -1.00

1979 45.00 2.00

1980 45.00 0.00

1981 45.00 0.00

1982 45.00 0.00

1983 44.30 -1.60

1984 46.10 -1.30

1985 45.00 2.00

1986 48.00 1.10

1987 45.00 1.70

1988 44.80 2.30

1989 45.50 -0.50

1990 45.00 2.40

1991 44.20 1.00

1992 46.60 1.50

1993 47.30 0.00

1994 48.60 1.00

1995 50.00 -0.50

1996 47.00 -1.00

1997 44.00 0.00

1998 46.50 0.50

1999 49.50 2.00

2000 46.00 1.00

2001 46.00 -1.00

2002 46.00 2.50

2003 48.00 2.00

2004 44.50 2.00

2005 47.00 0.50

2006 44.00 -0.50

2007

2008


for


38

Years Daily Maximum Temperature

(oC)

Daily Minimum Temperature (oC)

2009

2010

2011 46.00 0.00

2012 45.00 -15.00

2013 44.00 0.00

2014 44.00 1.00

2015 43.00 2.00


for


39

Annexure-B: Catchments Delineation of Major Streams/ Nullahs

Chaura Khwar at RD 7+060

Nullah at RD 8+650


for


40

Nullah at RD 8+890

Nullah at RD 9+580


for


41

Khyber Khwar at RD 21+920



for


42




for


43

Nullah at RD 24+700



for


44

Chigai Khwar at RD 25+810

Kagga Khwar at Wali Khel at RD 28+700


for


45

Dand Khwar at RD 30+460

Bori Khwar at RD 33+000


for


46

Sawal Khwar at RD 33+587

Nullah at RD 35+002


for


47

Nullah at RD 36+410

Nullah at RD 39+680


for


48

Wuch Tangi at RD 40+545

Nullah at RD 43+230


for


49

Nullah at RD 45+215

Giani at Torkham at RD 46+300


for


50

Annexure-C: Hydrologic and Hydraulic Parameters relating Bridges over Major Streams/ Nullahs

S.No. Location Name of Stream/

Nullah

Catchment Area

Main stream Length

Average Slope

Catchment 100-Year

Discharge

(Curve Number CN for SCS

Runoff=75)

Bridge Size

Channel Velocity at

Bridge Location (before bridge)

Channel Velocity

at Bridge

Location (with

bridge)

Flow Area at bridge

location (before bridge)

Flow Area at bridge

location (with

bridge)

HFL (before bridge)

HFL (with

bridge)

km2 Km m/m cumecs

Cell x Span

m/sec m/sec m2 m

2 m m

1 7+060 Chaura Khwar near Jamrud

425.31 38.70 0.0388 2356 7 x 40 2.81 2.86 837.20 824.65 479.22 479.30

2 8+650 Nullah 0.53 0.93 0.0690 12.72 1 x 30 0.49 0.55 26.12 23.05 532.79 532.78

3 8+890 Nullah 0.73 0.96 0.2190 17.5 1 x 40 0.63 0.64 27.60 27.14 537.06 537.06

4 9+580 Nullah 1.41 1.40 0.2764 34 1 x 40 0.92 1.10 36.91 30.90 538.11 538.11

5 21+920 Khyber Khwar at

Ali Masjid 70.00 20.00 0.0070 341 2 x 40 1.76 1.89 193.68 179.97 753.67 753.65

6 22+560 Khyber Khwar (RD22+560)

69.80 19.80 0.0071 340 2 x 30 1.77 2.15 192.48 158.17 771.94 771.91


69.60 19.60 0.0071 339 2 x 25 2.20 2.47 154.18 137.13 779.14 779.10


63.00 18.00 0.0361 307 4 x 30 1.48 1.55 207.35 197.46 803.90 803.91


for


51


Nullah

Catchment Area

Main stream Length

Average Slope

Catchment 100-Year

Discharge


Runoff=75)

Bridge Size

Channel Velocity at


Channel Velocity

at Bridge

Location (with

bridge)

Flow Area at bridge


Flow Area at bridge

location (with

bridge)

HFL (before bridge)

HFL (with

bridge)

km2 Km m/m cumecs

Cell x Span

m/sec m/sec m2 m

2 m m

9 24+700 Nullah 7.70 4.53 0.0838 92.3 2 x 35 0.94 1.43 97.89 64.43 823.24 823.28

10 25+615 Khyber Khwar (RD25+615)

56.00 16.00 0.0406 273 1 x 40 1.74 2.50 156.70 109.40 836.24 836.17

11 25+810 Chingai Khwar 3.29 2.33 0.3425 79 2 x 20 0.90 1.53 87.73 51.71 867.00 867.03

12 28+700 Kagga Khwar at

Wali Khel 8.45 3.49 0.2146 145 2 x 30 1.55 1.58 93.32 91.82 953.09 953.10

13 30+460 Dand Khwar 9.00 4.50 0.1756 154 1 x 25 1.75 2.02 87.91 76.33 958.68 958.63

14 33+000 Bori Khwar 6.80 4.00 0.1595 117 1 x 20 0.81 2.74 144.33 42.71 1003.48 1003.84

15 33+587 Sawal Khwar 9.00 4.50 0.1818 154 1 x 20 1.08 2.94 142.30 52.35 1013.74 1015.13

16 35+002 Nullah 1.36 1.60 0.1119 32.8 1 x 25 0.63 0.99 52.46 33.04 1019.76 1019.75

17 36+410 Nullah 5.60 3.20 0.1678 96 1 x 40 2.44 2.44 39.32 39.32 1024.87 1024.87

18 39+680 Nullah 0.80 1.76 0.1403 19.2 3 x 30 1.07 1.12 18.02 17.14 949.10 949.13

19 40+545 Wuch Tangi 9.75 6.50 0.1418 117 1 x 40 1.65 1.73 70.99 67.81 898.56 898.55


for


52


Nullah

Catchment Area

Main stream Length

Average Slope

Catchment 100-Year

Discharge


Runoff=75)

Bridge Size

Channel Velocity at


Channel Velocity

at Bridge

Location (with

bridge)

Flow Area at bridge


Flow Area at bridge

location (with

bridge)

HFL (before bridge)

HFL (with

bridge)

km2 Km m/m cumecs

Cell x Span

m/sec m/sec m2 m

2 m m

20 43+230 Nullah 3.20 5.10 0.2049 55 1 x 30 1.45 1.45 37.89 37.89 802.82 802.82

21 45+215 Nullah 15.00 8.00 0.1373 181 1 x 40 1.61 1.79 112.21 100.99 738.57 738.54

22 46+300 Giani at Torkham 29.20 8.00 0.1415 350 4 x 25 1.88 1.98 186.30 177.07 708.28 708.30


for


53

Annexure-D: Hydraulic Outputs of Major Streams/ Nullahs

0 50 100 150 200 250 300 350470

475

480

485

490

495

500

505

Bridge 7+060 Plan: Bridge 7+060 7/23/2017 Bridge of Chaura Khwar at RD 7+060 (Q=2356 cumecs)

Station (m)

Ele

vatio

n (

m)

Legend

EG PF 1

WS PF 1

Crit PF 1

Ground

Bank Sta

.025

0 50 100 150 200 250530

532

534

536

538

540

542

544

546

548

550

Bridge 8+650 Plan: Bridge 8+650 7/23/2017 Bridge of Nullah at RD 8+650 (Q= 12.72 cumecs)

Station (m)

Ele

vatio

n (

m)

Legend

EG PF 1

WS PF 1

Crit PF 1

Ground

Bank Sta

.025


for


54

0 20 40 60 80 100 120 140536

538

540

542

544

546

548

Bridge 8+890 Plan: Bridge 8+890 7/23/2017 Bridge of Nullah at RD 8+890 (Q= 17.50 cumecs)

Station (m)

Ele

vatio

n (

m)

Legend

EG PF 1

WS PF 1

Crit PF 1

Ground

Bank Sta

.025

0 50 100 150 200 250535

540

545

550

555

560

565

Bridge 9+590 Plan: Bridge 9+590 7/23/2017 Bridge of Nullah at RD 9+590 (Q= 34 cumecs)

Station (m)

Ele

vatio

n (

m)

Legend

EG PF 1

WS PF 1

Crit PF 1

Ground

Bank Sta

.025


for


55

0 20 40 60 80 100 120 140 160750

752

754

756

758

760

762

764

Bridge 21+920 Plan: Bridge 21+920 7/23/2017 Bridge of Khyber Khwar at RD 21+920 (Q=341 cumecs)

Station (m)

Ele

vation

(m

)

Legend

EG PF 1

WS PF 1

Crit PF 1

Ground

Bank Sta

.025

0 20 40 60 80 100 120 140 160765

770

775

780

785

790


Station (m)

Ele

vation

(m

)

Legend

EG PF 1

WS PF 1

Crit PF 1

Ground

Bank Sta

.025


for


56

0 20 40 60 80 100770

775

780

785

790

795


Station (m)

Ele

vatio

n (

m)

Legend

EG PF 1

WS PF 1

Crit PF 1

Ground

Bank Sta

.025

0 100 200 300 400 500800

802

804

806

808

810

812

814

816

818

Bridge 23+950 Plan: Bridge 23+950 7/23/2017 Bridge ofKhyber Khwar at RD 23+950 (Q= 307 cumecs)

Station (m)

Ele

vatio

n (

m)

Legend

EG PF 1

WS PF 1

Crit PF 1

Ground

Bank Sta

.025


for


57

0 20 40 60 80 100 120 140 160820

822

824

826

828

830

832

Bridge 24+700 Plan: Bridge 24+700 7/23/2017 Bridge of Nullah at RD 24+700 (Q=92.3 cumecs)

Station (m)

Ele

vatio

n (

m)

Legend

EG PF 1

WS PF 1

Crit PF 1

Ground

Bank Sta

.025

0 50 100 150 200 250 300832

834

836

838

840

842


Station (m)

Ele

vatio

n (

m)

Legend

EG PF 1

WS PF 1

Crit PF 1

Ground

Bank Sta

.025


for


58

0 20 40 60 80 100 120 140 160864

866

868

870

872

874

876

878

880

882

Bridge 25+810 Plan: Bridge 25+810 7/23/2017 Bridge of Chingai Khwar at RD 25+810 (Q=79 cumecs)

Station (m)

Ele

vatio

n (

m)

Legend

EG PF 1

WS PF 1

Crit PF 1

Ground

Bank Sta

.025

0 50 100 150 200950

952

954

956

958

960

Bridge 28+700 Plan: Bridge 28+700 7/23/2017 Bridge of Kagga Khwar at RD 28+700 (Q=145 cumecs)

Station (m)

Ele

vation

(m

)

Legend

EG PF 1

WS PF 1

Crit PF 1

Ground

Bank Sta

.025


for


59

0 50 100 150 200950

955

960

965

970

975

Bridge 30+460 Plan: Bridge 30+460 7/23/2017 Bridge of Dand Khwar at RD 30+460 (Q=154 cumecs)

Station (m)

Ele

vation

(m

)

Legend

EG PF 1

WS PF 1

Crit PF 1

Ground

Bank Sta

.025

0 50 100 150 200 2501001

1002

1003

1004

1005

1006

Bridge 33+000 Plan: Bridge 33+000 7/23/2017 Bridge of Bori Khwar at RD 33+000 (Q=117 cumecs)

Station (m)

Ele

vatio

n (

m)

Legend

EG PF 1

WS PF 1

Crit PF 1

Ground

Bank Sta

.025


for


60

0 50 100 150 200 250 300 3501010

1015

1020

1025

1030

1035

Bridge 33+590 Plan: Bridge 33+590 7/23/2017 Bridge of Sawal Khwar at RD 33+590 (Q=154 cumecs)

Station (m)

Ele

vatio

n (

m)

Legend

EG PF 1

WS PF 1

Crit PF 1

Ground

Bank Sta

.025

0 50 100 150 200 2501015

1020

1025

1030

1035

1040

1045

Bridge 35+002 Plan: Bridge35+002 7/23/2017 Bridge of Nullah at RD 35+002 (Q= 32.8 cumecs)

Station (m)

Ele

vatio

n (

m)

Legend

EG PF 1

WS PF 1

Crit PF 1

Ground

Bank Sta

.025


for


61

0 20 40 60 80 100 120 1401020

1030

1040

1050

1060

1070

Bridge 36+410 Plan: Bridge36+410 7/23/2017 Bridge of Nullah at RD 36+410 (Q= 96 cumecs)

Station (m)

Ele

vatio

n (

m)

Legend

EG PF 1

WS PF 1

Crit PF 1

Ground

Bank Sta

.025

0 50 100 150 200 250 300945

950

955

960

965

970

975

Bridge 39+680 Plan: Bridge 39+680 7/23/2017 Bridge of Nullah at RD 39+680 (Q=19.2 cumecs)

Station (m)

Ele

vatio

n (

m)

Legend

EG PF 1

WS PF 1

Crit PF 1

Ground

Bank Sta

.025


for


62

0 50 100 150 200 250 300 350 400890

900

910

920

930

940

950

960

Bridge 40+545 Plan: Bridge 40+545 7/23/2017 Bridge of Wuch Tangi at RD 40+545 (Q=117 cumecs)

Station (m)

Ele

vatio

n (

m)

Legend

EG PF 1

WS PF 1

Crit PF 1

Ground

Bank Sta

.025

0 10 20 30 40 50 60 70800

805

810

815

820

825

830


Station (m)

Ele

vation

(m

)

Legend

EG PF 1

WS PF 1

Crit PF 1

Ground

Bank Sta

.025


for


63

0 50 100 150 200 250 300 350735

740

745

750

755

760


Station (m)

Ele

vatio

n (

m)

Legend

EG PF 1

WS PF 1

Crit PF 1

Ground

Bank Sta

.025

0 50 100 150 200 250704

706

708

710

712

714

716

718

720


Station (m)

Ele

vation

(m

)

Legend

EG PF 1

WS PF 1

Crit PF 1

Ground

Bank Sta

.025


for


64

Annexure-E: Scour Depth Estimation by Lacey Regime Theory


for


65

S.# Location

D50

(Soil Type AASHTO

A-1-b)

Design 100-Year

Discharge Q

Lacey silt factor [1.76 SQRT(D50)]

P=4.75*sqrt(Q)

river width relation to select Lacey

Equation

L (actual channel

width)

Sy (scour depth)

mm cumecs f m m m

1 7+060 0.074 2356 0.479 230.559 228.000 8.02

2 8+650 0.074 12.72 0.479 16.941 32.650 1.26

3 8+890 0.074 17.5 0.479 19.871 38.490 1.33

4 9+580 0.074 34 0.479 27.697 26.250 1.96

5 21+920 0.074 341 0.479 87.714 75.890 4.21

6 22+560 0.074 340 0.479 87.586 57.73 3.11

7 22+765 0.074 339 0.479 87.457 43.560 3.42

8 23+950 0.074 307 0.479 83.227 111.750 4.07

9 24+700 0.074 92.3 0.479 45.635 75.010 1.85

10 25+615 0.074 273 0.479 78.483 45.960 3.12

11 25+810 0.074 79 0.479 42.219 42.770 2.59


for


66

S.# Location

D50

(Soil Type AASHTO

A-1-b)

Design 100-Year

Discharge Q

Lacey silt factor [1.76 SQRT(D50)]

P=4.75*sqrt(Q)

river width relation to select Lacey

Equation

L (actual channel

width)

Sy (scour depth)

mm cumecs f m m m

12 28+700 0.074 145 0.479 57.198 50.320 3.17

13 30+460 0.074 154 0.479 58.946 29.710 2.98

14 33+000 0.074 117 0.479 51.379 25.380 2.87

15 33+587 0.074 154 0.479 58.946 27.710 3.05

16 35+002 0.074 32.8 0.479 27.204 29.870 1.93

17 36+410 0.074 96 0.479 46.540 27.900 2.60

18 39+680 0.074 19.2 0.479 20.813 19.470 1.62

19 40+545 0.074 117 0.479 51.379 30.160 2.71

20 43+230 0.074 55 0.479 35.227 23.580 2.29

21 45+215 0.074 181 0.479 63.905 45.850 2.73

22 46+300 0.074 350 0.479 88.864 79.590 4.25

hydraulic & hydrology study report peshawar tortham

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