ACTIVITY

WEEK 10

Lecture (3 hours)

Week 11 : Coverage : Methods of monitoring settlement

and horizontal movement

LEARNING OUTCOMES

Learning outcomes:

At the end of this lecture/week the students would

be able to:

Discuss horizontal movements using

inclinometers

Discuss the methods for monitoring settlement

using settlement marker

INCLINOMETER

• Application of Inclinometer

An inclinometer or clinometer is an instrument for measuring angles of slope (or tilt), elevation or inclination of an object with respect to gravity. It is also known as a tilt meter, tilt indicator, slope alert, slope gauge, gradient meter, gradiometer, level gauge, level meter, declinometer, and pitch & roll indicator. Clinometers measure both inclines (positive slopes, as seen by an observer looking upwards) and declines (negative slopes, as seen by an observer looking downward).

PIEZOMETER RESULT

• Groundwater level was monitored from three

(3) installed standpipes piezometer at BH1,

BH2 and BH3

• The higher are approximately RL 367.30m

(BH1) = 5.57m below existing ground

• The lowest are approximately RL 355.41m

(BH3) = 2.20m below existing ground

• Detail data collection for Piezometer Pipe.

MACKINTOSH PROBE

• Locations of Mackintosh Probe

• The purpose of Mackintosh Probe were carried

out to get a significant indication of the subsoil

in situ strength in residual soil weathering

grade

• This test is more cheaper compared to

borehole.

CORELATION OF MACKINTOSH

PROBE AND BEARING CAPACITY

LABORATORY TEST

• TRIAXIAL TEST

- Unsonlidated Undrained

Test (UU)

- Parameter Obtain

a. Cohesion, C kN/m2

b. Angle Friction, 0

• Provide adequate information for site

assessment, safe and economical designs of

temporary and permanent works.

PROJECT BRIEF

• NAME OF PROJECT : PEMBINAAN PANGKALAN PASUKAN

POLIS MARIN DI PELABUHAN KLANG

(FASA I) SELANGOR DARUL EHSAN

• LOCATION : PULAU INDAH, SELANGOR D.E.

• CLIENT : JABATAN KERJA RAYA(CAWANGAN

PANGKALAN UDARA & MARITIM

• CONTRACTOR : PULAU REKA-KEMBANG MAJU J.V.

• INSTRUMENTATION

MONITORING & CONTRACTOR : TECHNIQUES GEOSYSTEM

• PROJECT COST : RM 54,500,000.00

SCOPE OF WORKS

• The Objective of Works To Be Carried Out:

-Understanding subsurface condition

and geology at study area.

-Understanding settlement problem by

using Terzaghi and Superposition

Method.

• Con’t

-Understanding settlement and

consolidation without treatment.

-During construction

-Post construction

-Understanding settlement and

consolidation with treatment.

-Design Parameters and laboratory

testing.

Geology And Subsurface Conditions

• North Port area, where the soils is marine clay.

• Sometime the water level is high and saturated.

• The location is too close to the beach.

• Strength of soils:

-Very soft clay / silt SPT-N 0-2

-Soft clay / silt SPT-N 2-4

Borehole Machine and Samples

• Type of machine is wash drilling machine

-3 borehole were drilled for this project.

• Types of samples is disturb, undisturbed, and mazier samples.

• Termination of BH1 is 11.00 meters, BH 2 is 10.50 meters and BH3 is 11.00 meters.

• Subsoil of cohesive soil consist of :

-Very Soft Clay SPT-N Value (0 – 2)

-Soft Clay SPT-N Value (2 - 4)

-Firm SPT-N Value (4 – 8)

-Stiff SPT – N Value (8 – 15)

-Very Stiff SPT – N Value (15 – 30)

-Hard SPT –N Value ( >30)

Borehole Machine on Site

Con’t

Con’t

Con’t

Con’t

Con’t

Con’t

•Result of borehole

RELATIONSHIP BETWEEN TRIAXIAL AND SITE

CONDITION

(Settlement and Consolidation)

Settlement

• Design Data

-Settlement

Hd Ce log(PoP1)

(1+e) Po

- From sample UD1.

- Result Odometer Test.

- Plot graph Void Ratio Vs Applied Pressure

-Obtained design parameters such as:

eo,Cc,Po,P1 and Hd.

-Finally Sf=Si+Sp+Sc (Principle of Superposition)

DEGREE OF CONSOLIDATION

• By using formula :

Tv =Cv t Refer to graph

Hd2 Tv Vs Uav Uav %

Then Settlement During Construction

Settlement Post Construction

(Settlement Without Treatment)

• Where Consolidation With Treatment

-Based on time for rest period in percentage.

-Based on principle of superposition, Sc

INSTALLATION OF SURFACE SETTLEMENT MARKERS

• To monitor vertical movement of the ground or

embankment surface

• Location of SSM – Instruction from the Engineer

• Steel rod – 20mm diameter

• Minimum driven distance – 0.5m

• Surrounded by 300mm x 300mm x 300mm

of concrete

SEQUENCE OF INSTALLING SETTLEMENT MARKER

SEQUENCE OF INSTALLING SETTLEMENT MARKER

INSTALLATION OF ROD SETTLEMENT GAUGES

• To measure settlement taking place beneath and adjacent to embankment

• Location of SSM – Instruction from the Engineer

• Base plate and first length of RSG shall put in place

during earthwork

• Extension length of RSG shall be install

when compacted embankment is 250 mm

SEQUENCE OF INSTALLING SETTLEMENT MARKER

SEQUENCE OF INSTALLING SETTLEMENT MARKER

LOCATION OF TEST INSTRUMENTS

Deep Settlement Gauge Settlement MarkerPiezometer

MONITORING OF INSTRUMENTS

• Monitored by standard leveling technique

• Levels shall be taken from the top of the rod.

• One point taken into consideration

• Following records are required

REPORTING

• A tabulated data and plot of settlement against time.

• Detail result

RECORD REQUIRED

• Reduced level of top of rod

• Original ground level at gauge location

• Reduced level of ground at adjacent to gauge

• Record of fill placed

• Total thickness of fill

• Record of extensions

• Settlement of plate relative to the base readings and previous

reading

REPORTING OF RSG

• A tabulated data and plot of thickness of fill and

settlement of plate against time.

• Detail result

RESULT FROM

TABULATED DATA

RESULT FROM

TABULATED DATA

• S.I is compulsory for every project.

• From S.I. result, engineer can design the best solution

to improve ground condition in effective and

economic approached.

• Must know 2 W, 1H

CONCLUSION