state project no. 56-299 town project no. 06-44 … · safely carry the hl-93 legal load. design...

REHABILIATION OF BRIDGE NO. 05491

BAILIWICK ROAD OVER BYRAM RIVER

GREENWICH, CONNECTICUT

STATE PROJECT NO. 56-299

TOWN PROJECT NO. 06-44

STRUCTURE TYPE STUDY REPORT

OCTOBER 2011

Prepared By:

Dewberry-Goodkind, Inc.

59 Elm Street, Suite 101

New Haven

Structure Type Study

Rehabilitation of Bridge No. 05491

Bailiwick Road over Byram River

Greenwich, Connecticut

TOC-1

Table of Contents

Description Page

1. Project Description 1

2. Bridge Evaluation Methodology 2

3. Proposed Bridge Rehabilitation/Replacement 4

3.1 Alternative 1: Bridge Replacement 4

3.1.1 Design 4

3.1.2 Constructability 5

3.1.3 Cost Estimate 5

3.1.4 Benefits 5

3.2 Alternative 2: Bridge Rehabilitation with addition of Relief Culverts 6

3.2.1 Design 6

3.2.2 Constructability 7

3.2.3 Cost Estimate 7

3.2.4 Benefits 8

4. Summary, Conclusions & Recommendations 8

Appendix A – Location Map

Appendix B – Photos

Appendix C – Sketches

Appendix D – Construction Schedule

Appendix E – Cost Estimate

Appendix F – Alternative 1 Superstructure Computations

Appendix G – Alternative 2 Arch Analysis & Load Rating Computations





1

Report

1. PROJECT DESCRIPTION

Bridge No. 05491 carries Bailiwick Road, an urban local road, over the Byram River in the Town of Greenwich (Town), Connecticut. The bridge is located approximately fifty-five feet west of the intersection of Bailiwick Road with Riversville Road (see Location Map, Appendix

A) and provides the only official access to a community of approximately 200 residents. The Average Daily Traffic (ADT) on the bridge is 595 vehicles (Year 2010) based on information available with the Connecticut Department of Transportation (ConnDOT). The 32 foot long (chord length) single span arch shaped bridge carries one lane of vehicular traffic in the eastbound and westbound directions over a roadway with a 30 foot width. In addition, the bridge carries an approximately 5’-0” wide grass walkway along the south fascia. The bridge is located within the limits of a slightly curved horizontal roadway alignment with a crest vertical curvature. According to information available with ConnDOT, the bridge was originally constructed in 1970. The bridge superstructure consists of a reinforced concrete deck arch with masonry facing present on the fascias. Spandrel walls comprising of grouted stone masonry retains the fill above the arch and act as parapets at the two fascias. The spandrel walls/parapets are of “gravity” type construction and cannot support current vehicular impact loads since they are not positively attached to the deck. The arches are supported by reinforced concrete footings which are founded on bedrock based on information contained in the original design plans. The approach roadway is contained by stone masonry wingwalls with parapets.

During a major storm event that took place on April 15, 2007, the Bailiwick Road Bridge which is hydraulically deficient, sustained damage as a result of the Byram River overtopping the bridge. The damage included the detachment of the north (i.e. upstream) parapet and rail system from the bridge structure and failure of the bituminous concrete pavement resulting in the closure of the bridge. The Town was able to detour traffic via a private roadway belonging to Bailiwick Club (see Aerial View of Project Site, Appendix A). Subsequently, the Town was able to reopen the bridge by installing temporary precast concrete barriers along the fascias to act as parapets and by reconstructing the roadway pavement over the arch bridge. The Town has since replaced the storm damaged parapet with funding available from the Federal Emergency Management Agency (FEMA).

Photos of the existing bridge are attached as Appendix B. A general-plan, elevation and cross section of the existing bridge is depicted as Sketch 1 in Appendix C.

Since a formal load rating evaluation has not been performed by ConnDOT, the Bailiwick Road Bridge is assumed to have an inventory load rating capacity of 34 tons for an HS-20 vehicle based on judgment. This is slightly less than the minimum 36 tons required per the American





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Association of State Highway & Transportation Officials (AASHTO) Standards. A visit to the bridge site and review of the 2009 ConnDOT Inspection Report (subsequent to repairs made by the Town) indicates the superstructure (i.e. concrete arch) and the substructures (i.e. concrete arch walls, footings and masonry wingwalls) to be in “Satisfactory” condition. The underside of the arch exhibits isolated cracks with efflorescence and areas with honeycombing while the masonry facing exhibits missing/deteriorated mortared joints. There are a few spalls and voids present near the water line at the concrete arch walls while the masonry wingwalls exhibit missing/deteriorated mortared joints. No formal in-depth inspection was performed as part of the Structure Type Study. Since the repairs performed subsequent to the 2007 storm damage are temporary in nature and the bridge provides the only official access to the residential community, the bridge is being studied for rehabilitation/replacement. The primary goals of the project are to improve the hydraulic capacity of the bridge to provide relief from flooding arising from lower frequency storm events and to ensure that bridge/roadway can be reopened quickly to vehicular traffic subsequent to a higher frequency overtopping event similar to that of the April 2007 storm. Based on a preliminary hydraulic analysis performed by Dewberry, the results of which were summarized in a memorandum and submitted to the Town/ConnDOT in August 2011, the following alternatives were proposed for investigation in the Structure Type Study:

1. Alternative 1 – Bridge replacement 2. Alternative 2 – Bridge rehabilitation with addition of relief culverts 3. Alternative 3 – Bridge rehabilitation with lowering of west approach roadway

Since the preliminary hydraulic analysis indicated no reductions in the upstream water surface elevations, compared to existing conditions, that would alleviate flooding arising from lower frequency storm events by simply lowering the west approach roadway, Alternative 3 was not investigated further.

A geotechnical investigation comprising of three soil borings was initiated to obtain information about the soil conditions in order to determine the existing/proposed foundation capacities, verify the ability of the foundations to withstand design scour conditions and help in determining the need for any countermeasures. The boring locations are depicted in Sketches 2 and 3, in Appendix C. Since shallow bedrock elevations were observed with the soil borings, scour is not anticipated to be a concern on this project. The results of the geotechnical investigations will be submitted separately to the Town as an independent Foundations Report. 2. BRIDGE EVALUATION METHODOLOGY

The ability of a bridge to carry legal loads is determined from the minimum load rating capacity of its member components. The legal load for new bridge construction is an HL-93 design vehicle (see Figure 1) according to the AASHTO LRFD Design Specifications. The HL-93 loading comprises of:





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a) Design Truck or Design Tandem whichever produces maximum forces; combined with b) Design Lane Load

The Design Truck is a 3-axle 28 to 44 foot long vehicle weighing 36 tons while the Design Tandem is a 2-axle 4 foot long vehicle weighing 25 Tons. The Design Lane load is a uniform load of 640 pounds/feet applied in combination with the aforementioned loads. The governing load ratings are determined for an "as-inspected" condition of the bridge accounting for section losses (if present) and are calculated at two levels, Inventory and Operating. The Inventory Rating represents an allowable live load that can safely use the bridge for an “indefinite” period of time. The Operating Rating describes the “maximum” permissible live load to which the bridge may be subjected. Unlimited usage of the bridge by vehicles at the Operating level will shorten the useful life of the structure. The Inventory Rating Factor for a member is obtained by subtracting the dead load effects on the member from the member capacity and dividing the results by the effects of the HL-93 live loads. The calculated dead loads are increased by 25% (components and attachments to the bridge) to 50% (wearing surface on the bridge) while the live loads are increased by 75% to account for uncertainties. In summary,

Inventory Rating Factor = Member Capacity - 1.25 to 1.50*(Dead Loads)

1.75*(Live Loads)

An Inventory Rating Factor greater than or equal to 1.0 indicates the ability of the member to safely carry the HL-93 legal load.

Design Truck + Lane Load

Design Tandem + Lane Load

Figure 1 – AASHTO HL-93 Vehicle





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3. PROPOSED BRIDGE REPLACEMENT/REHABILITATION

3.1 ALTERNATIVE 1: BRIDGE REPLACEMENT

3.1.1 DESIGN

As mentioned previously, the primary goal of the project is to increase the hydraulic opening under the bridge so as to alleviate flooding concerns at least from the lower frequency storm events. In order to improve the hydraulic opening, a hydraulics analysis of the following three bridge replacement types was performed:

1. A new 3-sided 32-foot long by 8-foot high precast concrete structure (Conspan Bridge) with proposed intrados elevation matching existing (i.e. El. 130.8 +/-).

2. A new multi-girder single span bridge with a 50-foot opening and a low chord elevation matching existing arch intrados elevation 130.8 +/-.

3. A new multi-girder single span bridge with a 32-foot opening (matching the span of the existing bridge) and a low chord raised slightly to an elevation of 131.00

Based on the preliminary hydraulic analysis, a multi-girder single span bridge with a 50-foot opening was determined to provide the maximum hydraulic benefits due to approximately 5.3 inches and 3 inches reduction in the upstream water surface elevations from a 2-yr and a 10-yr storm event respectively. A solid parapet was utilized in the hydraulic model for the aforementioned bridge replacement alternatives. If an open bridge rail system is utilized in lieu of a solid concrete parapet, the water surface elevations are likely to be lowered even further offering additional hydraulic benefits. However, the permitting agencies are unlikely to approve substantial increases in the reduction of the water surface elevations without determining its impact downstream of the bridge site. Therefore, a 50-foot bridge opening utilizing concrete parapets was selected as Alternative 1 for the structure type study. In this alternative, the existing concrete arch bridge and the wingwalls will be removed in its entirety. New concrete abutments supported by spread footings founded on bedrock will be constructed to support a new bridge superstructure comprising of a reinforced concrete deck made composite with maintenance free weathering steel rolled beams. The 53’-0” long bridge span length will provide a 50’-0” long opening consistent with the aforementioned hydraulics studies. The steel beams were designed utilizing the PennnDOT computer program STLRFD for the dead loads due to its self weight and weight of the proposed concrete deck, parapet, railing and wearing surface and live loads due to an AASHTO HL-93 design vehicle. A yield stress of 50 ksi was assumed in the analysis based on AASHTO M270 Grade 50WT2 steel typically specified for structural steel. Rolled beams sections W 21 x 101 were determined to be necessary to support the bridge loads and the governing Inventory Rating Factor was determined to be 1.21. An overall structure depth of 34 inches will require the roadway at the bridge to be raised by 14 inches in this alternative.





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Reinforced concrete wingwalls will be designed to contain the approach roadway. A rigid concrete pavement will be utilized to construct the roadway approaches in order to eliminate pavement washouts during storm events and to facilitate a quicker reopening of the bridge subsequent to overtopping events. To improve aesthetics, exposed concrete surfaces can either be provided with a masonry facing or less expensive form liners can be utilized to provide an appearance of stone masonry. The bridge rail system will consist of a 2’-8” high concrete parapet and a single aluminum rail anodized to color brown. Box beam type weathering steel approach guiderails painted to color brown is proposed to provide for traffic safety at the roadway approaches to the bridge. It should be noted that the type and color of the proposed bridge and the approach guide rail system can be changed during the final design phase of the project based on the needs of the Town and input from the resident community. The general-plan, elevation and cross section of the proposed bridge configuration is depicted in Sketch 2 (Appendix C) and the computations of the superstructure analysis are attached as Appendix F. 3.1.2 CONSTRUCTABILITY

In order to accomplish the replacement, the bridge will be closed and vehicular traffic detoured via the private roadway belonging to the Bailiwick Club (see Aerial View of Project Site, Appendix A). A debris shield will be installed below the arch prior to demolishing the existing bridge in order to prevent any debris from falling into the river. Subsequent to the installation of cofferdams and temporary earth retaining systems, the existing arch footings and wingwalls will be removed and the new abutments, wingwalls and footings will be constructed in the dry. Structural steel beams will be erected utilizing cranes followed by the construction of the deck and parapets and the bridge will be opened to traffic after completion of the approach roadway work. The construction duration is estimated to be approximately 7 months (See Appendix D).

3.1.3 COST ESTIMATE

The proposed bridge replacement (year 2011 pricing) is estimated to cost $1,390,000 excluding costs associated with incidentals and contingencies (see Appendix E). The construction cost is estimated to be $1,880,000 if 35% is assumed as costs for incidentals and contingencies. 3.1.4 BENEFITS

The bridge replacement alternative will provide the following benefits:

a) Increase in hydraulic opening will minimize overtopping events especially during the lower frequency storms.

b) The presence of a rigid concrete pavement at the roadway approaches and a new stronger bridge will ensure that the bridge can be quickly reopened to vehicular traffic subsequent to overtopping events from higher frequency storms.

c) A bridge structure that does not encroach into the channel resulting in reduced scour depths and which would be looked upon favorably by the permitting agencies.





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d) A new bridge with a service life of 50-75 years. e) Weathering steel beams are likely to be maintenance free during its service life without a

need for field painting. f) Conduits can be installed for future utility crossings between the beams providing an

opportunity to the Town.

3.2 ALTERNATIVE 2: BRIDGE REHABILITATION WITH ADDITION OF RELIEF

CULVERTS

3.2.1 DESIGN

In order to improve the hydraulic opening at the site while maintaining the existing bridge, installation of two (2) 9-foot wide by 4-foot high concrete box culverts located west of the existing bridge was considered. A hydraulics analysis indicates that the addition of relief culverts will reduce the upstream water surface elevations by approximately 2.3 inches and 1.3 inches from a 2-yr and the 10-yr storm event respectively. In this alternative, the existing arch bridge was studied for rehabilitation with the aim that it could be reopened quickly subsequent to a major overtopping event. In order to verify that the existing bridge had adequate capacity, a structural analysis of the arch was performed utilizing the Bentley computer program STAAD to determine the dead and live load forces. The dead loads acting on the arch include its own self weight and the weight of the proposed backfill, pavement and parapets and the lateral earth pressure resulting from the soil present behind the arches. The arch was modeled in STAAD utilizing beam elements since they are subjected to both axial forces and bending moments. The AASHTO HL-93 live load was modeled as a moving load and simulated to run on a fictitious roadway from the west (left) end to the east (right) end of the bridge model. A 3’-6” soil surcharge was used to model the load cases when an axle of the 28 foot long HL-93 truck was outside the bridge on the roadway approach.

The arch section properties were calculated and column interaction diagrams were developed for combined axial loads and bending moments using Excel spread sheets. Since the material properties of the existing concrete and reinforcing steel are not provided on the Original Construction Plans, a compressive strength of 2,500 psi for arch concrete and a yield stress of 40 ksi for reinforcing steel were assumed in accordance with the AASHTO Manual for Bridge Evaluation. The dead and live loads obtained from the STAAD analysis were combined to obtain the inventory ratings for the arch, utilizing the aforementioned interaction diagrams, at the support, crown and ¼ point locations. The governing Inventory Rating Factor of the arch was calculated to be 1.24 at the abutment indicating that the existing bridge has adequate capacity to support future loads. In Alternative 2, the existing flexible bituminous concrete pavement and fill material present above the arch will be removed to repair any concrete deterioration present on the arch extrados.





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The concrete deterioration in the arch intrados will be repaired from the underside utilizing shielding and work platforms. Subsequent to the arch repairs, the stone masonry spandrel walls will be replaced with a concrete wall that will be attached to the arch to prevent its failure prior to backfilling the arch with granular fill. A moment slab will be installed to resist vehicular traffic impact loads from the parapet in order to meet current safety standards. An 8” thick rigid concrete pavement will be installed both on the bridge and the roadway approaches to prevent its washout during potential storm overtopping events. This alternative will also require the roadway at the bridge to be raised by 14 inches. The existing stone masonry wingwalls will be removed in their entirety and replaced with reinforced concrete wingwalls that will be extended to the headwall of the proposed culverts at the west approach. In order to provide for improved aesthetics and an appearance that is uniform and similar to the existing bridge, masonry facing will be provided on all exposed concrete surfaces. Similar to Alternative 1, the bridge rail system will consist of 2’-8” high concrete parapets and a single aluminum rail anodized to color brown. Box beam type weathering steel approach guiderails painted to color brown is proposed to protect traffic at the roadway approaches beyond the limits of the bridge. As mentioned previously, the bridge and approach guide rail system can be changed during the final design phase of the project depending upon the needs of the Town and input from the resident community. The general-plan, elevation and cross section of the proposed bridge configuration is depicted in Sketch 3 (Appendix C) and the computations of the arch analysis are attached as Appendix G. 3.2.2 CONSTRUCTABILITY Similar to Alternative 1, the existing bridge will be closed and the vehicular traffic detoured via the private roadway belonging to the Bailiwick Club to accomplish the construction. The arch extrados will be repaired subsequent to the removal of the existing pavement and fill material and the concrete deterioration in the arch intrados will be repaired from the underside utilizing shielding and work platforms. A concrete spandrel wall along with moment slab will be constructed at the fascias and the arch will be backfilled. Subsequent to the installation of cofferdams and temporary earth retaining systems, existing wingwalls will be removed, new relief culverts installed followed by the construction of new wingwalls and headwalls. The bridge will be reopened to vehicular traffic after completion of the approach roadway work including the installation of an 8” thick rigid concrete pavement. The construction duration is estimated to be approximately 7 months (See Appendix D) similar to Alternative 1.

3.2.3 COST ESTIMATE The proposed bridge rehabilitation (year 2011 pricing) is estimated to cost $1,350,000 excluding costs associated with incidentals and contingencies (see Appendix E). The construction cost is estimated to be $1,830,000 if 35% is assumed as costs for incidentals and contingencies.





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3.2.4 BENEFITS

The bridge rehabilitation alternative will provide the following benefits:

a) Slight improvement in hydraulic opening will result in some reduction of overtopping events especially during the lower frequency storms.

b) The presence of a rigid reinforced concrete pavement and spandrel walls positively attached to the arch will ensure that the bridge can be quickly reopened to vehicular traffic subsequent to overtopping events from the higher frequency storms.

c) A rehabilitated bridge with a service life of 30-40 years. d) While conduits can be installed above the arch for future utility crossings, their size will

be limited by the fill depth and cover requirements.

The main drawbacks with this alternative are the smaller increase in the hydraulic opening and the addition of culverts to the Town’s bridge inventory requiring their long term maintenance.

4. SUMMARY, CONCLUSIONS & RECOMMENDATIONS

The goals of the project are to improve the hydraulic capacity of the bridge and to ensure that the Bailiwick Road Bridge and the approach roadways can be reopened quickly to vehicular traffic subsequent to major storm events so that the community comprising of approximately 200 residents do not feel stranded as this bridge provides their only official access for ingress and egress. Based on a preliminary hydraulic analysis performed by Dewberry, the following alternatives were proposed for investigation in the Structure Type Study:

1. Alternative 1 – Bridge replacement 2. Alternative 2 – Bridge rehabilitation with addition of relief culverts 3. Alternative 3 – Bridge rehabilitation with lowering of west approach roadway

Based on the preliminary hydraulic analysis, a new multi-girder single span bridge with a 50-foot opening was determined to provide the maximum hydraulic benefits due to reductions of approximately 5.3 inches and 3 inches in the upstream water surface elevations from a 2-yr and a 10-yr storm event respectively. It was determined that the installation of two (2) 9-foot wide by 4-foot high concrete relief culverts installed west of the existing bridge would reduce the upstream water surface elevations by approximately 2.3 inches and 1.3 inches for the 2-yr and the 10-yr storm event respectively. It was determined that there were no benefits or reductions in the upstream water surface elevations by simply lowering the west approach roadway and therefore Alternative 3 was not further investigated in this study. A geotechnical investigation comprising of three soil borings was initiated to obtain information about the soil conditions in order to determine the existing/proposed foundation capacities, verify the ability of the foundations to withstand design scour conditions and help in determining the need for any countermeasures. The presence of shallow bedrock elevations indicates that shallow spread footings founded on bedrock will be adequate to support the proposed bridge structure





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and that scour will not be a challenge. The results of the geotechnical investigations will be submitted separately to the Town/ConnDOT as an independent Foundations Report.

In Alternative 1, the existing concrete arch, footings and the wingwalls will be removed in their entirety. New concrete abutments and wingwalls supported by spread footings founded on bedrock will be constructed to support a new 53’-0” long bridge with a reinforced concrete deck made composite with maintenance free weathering steel rolled beams to provide for a 50’-0” wide hydraulic opening. A rigid concrete pavement will be utilized to construct the roadway approaches to eliminate pavement washouts during storm events and to facilitate a quicker reopening of the bridge subsequent to overtopping events. Form liners will be used on all exposed concrete surfaces to provide an appearance of stone masonry for improved aesthetics. In Alternative 2, the existing arch bridge was studied for rehabilitation with the aim that it could be reopened quickly subsequent to a major overtopping event. A structural analysis of the arch indicates that the bridge has adequate capacity to support future loads. In this alternative, the existing bituminous concrete pavement and backfill material present above the arch will be removed prior to repairing potential concrete deterioration present on the arch intrados and extrados. The stone masonry spandrel walls will be replaced with a concrete wall positively attached to the arch to prevent its failure. A moment slab will be installed to resist vehicular traffic impact loads from the parapet in order to meet current safety standards and an 8” thick rigid concrete pavement will be installed both on the bridge and the roadway approaches to prevent its washout during potential storm events. The existing stone masonry wingwalls will be removed in its entirety and replaced with reinforced concrete wingwalls that will be extended to the headwall of the proposed relief culverts to be installed west of the existing bridge. In order to provide for improved aesthetics and an appearance that is uniform, consistent and similar to the existing bridge, masonry facing will be provided on all exposed concrete surfaces.

The bridge rail system in both the alternatives will consist of a 2’-8” high concrete parapet and a single aluminum rail anodized to color brown. This rail system was utilized in the hydraulics model since it is believed that even though the use of an alternative open bridge rail system would result in additional hydraulics benefits (i.e. further reductions in upstream water surface elevations), the permitting process would likely be more challenging without a prior evaluation of impacts downstream of the bridge site. The Town may consider further investigating this option in the Final Design Phase of the project. Box beam type weathering steel approach guiderails painted to color brown is proposed to protect traffic at the roadway approaches beyond the limits of the bridge. The type and color of the proposed bridge and the approach guide rail system can be changed during the final design phase of the project based on the needs of the Town and input from the resident community. Cofferdams and temporary earth retaining systems will be required in both the alternatives in order to excavate and remove the existing structure and to accomplish the proposed construction in the dry. A debris shield will be installed below the arch prior to demolishing the existing bridge (Alternative 1) or performing arch repairs (Alternative 2) in order to prevent any debris from falling into the river. In both the alternatives, the bridge will be closed and the vehicular





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traffic detoured via the private roadway belonging to the Bailiwick Club during construction. The construction duration for both the alternatives is estimated to be approximately 7 months.

The proposed replacement/rehabilitation is estimated to cost $1,880,000 and $1,830,000 for Alternatives 1 and 2 respectively assuming 25% and 10% for incidental and contingency costs respectively.

Even though the bridge replacement alternative is estimated to be slightly more expensive, improvement in hydraulic opening and minimizing potential overtopping during the lower frequency storm events, a bridge structure not encroaching into the channel aiding the permitting approval process and a new stronger bridge with a rigid concrete pavement that will not washout and ensure that the bridge and the roadway can be quickly reopened to vehicular traffic subsequent to storm events are some of the main benefits with this alternative. Other benefits with this alternative include a new bridge with a service life of 50-75 years, maintenance free nature of weathering steel beams and the feasibility of installing conduits for future utility crossings. For nearly the same cost as Alternative 1, the bridge rehabilitation alternative will provide for a somewhat lesser hydraulics improvement; however a rehabilitated bridge with a service life of 30-40 years and the presence of a rigid reinforced concrete pavement and a spandrel wall positively attached to the arch will ensure that the bridge can be quickly reopened to vehicular traffic subsequent to overtopping events. The Town will be required to maintain an additional bridge comprising of the two relief culverts. Based on the benefits, cost estimate and duration of construction, we recommend the selection of Alternative 1 with the construction of a new bridge. It is also recommended that the Town investigate the feasibility of further improving the hydraulics by conducting a downstream impact analysis.





Appendix A

Location Map

Location Map

Bridge 05491

Byram River

Aerial View of Project Site

Bridge 05491

Bailiwick Club

Private Road/

Potential Detour





Appendix B

Photos


New Haven, CT 06510

STRUCTURE TYPE STUDY

BRIDGE NO. 05491,BAILIWICK ROAD OVER BYRAM RIVER

GREENWICH, CT

Photo Sheet

1 of 3

Photo 1: North elevation of bridge. Note detached Photo 2: South elevation of bridge.

parapet.

Photo 3: Bridge from east approach. Photo 4: Bridge from west approach.


New Haven, CT 06510



GREENWICH, CT

Photo Sheet

2 of 3

Photo 5: Remnants of rubble stone masonry spandrel Photo 6: Existing bridge rail system at south fascia.

wall/parapet at north fascia.

Photo 7: Condition of arch underside (west half). Photo 8: Condition of arch underside (east half).


New Haven, CT 06510



GREENWICH, CT

Photo Sheet

3 of 3

Photo 9: Condition of NE stone masonry wingwall. Photo 10: Missing stones in wingwall parapet.





Appendix C

Sketches

1 in.

TW 10/16 i

n.

Q 8 in.

4 in. 8 in.

3 in.

3 in.

36 in.

2 in.

2 in.

2 in.

2 in.

2 in.

2 in.

4 in.

3 in.1 in.

32 in.

6x1 in.

TW 5 in.

8 in.

80134

CL&P

8134A

CL&P

WF 46

WF 47WF 30

WF 31

WF 26WF 1

NO OUTLETSIGNNO PARK

SIGN

AT&TUGUF

CATVUGUF

CL&PUGUF

BIT. L.O.

BIT. L.O.

JPG-3 (I. P

IN)

No. 05491

BRIDGE

AQUARION W

ATER CO.

EXPOSED WATER M

AIN

- -

-

-

-

- -

- - -

- - - -

- - -

- - -

- - - -

REHABILITATION OF BRIDGE

NO. 05491 BAILIWICK ROAD

OVER BYRAM RIVER

GREENWICH 56-299

{ BAILIWICK ROAD

36’-6"|

VA

RIES

SCALE: �" = 1’-0"

SCALE: 1" = 10’

GENERAL PLAN AND

CROSS SECTION

38’-0"|

VARIES)

ARCH SLAB (THICKNESS

(THICKNESS VARIES)

GRANULAR FILL

(TYP.)

SPANDREL WALL/PARAPET

STONE MASONRY4"| ASPHALT PAVEMENT

P.A.G.

(T

YP.)

6"

(TYP.)

FACING

MASONRY

15’-0"|PAVEMENT

EDGE OF

PAVEMENT

EDGE OF

WINGWALL 1A

WINGWALL 1B

GRASS WALKWAY

ARCH BRIDGE

EXIST. CONCRETE

GENERAL PLANSCALE: 1" = 10’

RIVER

BYRAM

WINGWALL 2B

APPROX. { BAILIWICK ROAD

COMPANY)

(AQUARION WATER

EXISTING WATER MAIN

WINGWALL 2A

SOUTH ELEVATION

(TYP.)

EL. 120.6|

33’-8�"

(ELEVATION VARIES)

WATERLINE

ORDINARY HIGH 4"X4" STEEL TUBE RAIL

MASONRY WINGWALL (TYP.)

CEMENT RUBBLE STONE

(TYP.)

EL. 127.4|

EL. 130.8|

EXIST. ROADWAY

T.STRNAD/S.ERDAS

A. SESHADRI

1ELEVATION-EXISTING BRIDGE

EXIST. GRADE

30’-0"

(SURVEY)

CHANNEL BED

APPROX. EXIST.

TUBE RAIL (TYP.)

4"X4" STEEL

1’-6"|

LANE

15’-0"|

LANE

15’-0"|

GRASS WALKWAY

5’-0"| 1’-6"|

ROAD

} BAILIWICK

WALL

FACE OF WALL

FACE OF

1’-6"|

5’-0"|

15’-0"|

1’-6"|

FACING

WITH MASONRY

CONCRETE ARCH

STRUCTURE STUDY REPORT

DESIGNER/DRAFTER:

CHECKED BY:

PROJECT TITLE: TOWN:

DRAWING TITLE:

PROJECT NO.

DRAWING NO.

SKETCH NO.

Filename:SHEET NO.REVISION DESCRIPTIONDATEREV.

DEPARTMENT OF PUBLIC WORKS

TOWN OF GREENWICH

SCALE AS NOTED

10/6/2011

BLOCK:

SIGNATURE/

DATE: APPROVED BY:


...\SB_MSH_056_0299_GPN-EXIST.dgnPlotted Date:

E 748231.49

N 578938.37

STA 105+41.46

PC

106+00

105+00

1 in.

TW 10/16 i

n.

Q 8 in.

4 in. 8 in.

3 in.

3 in.

36 in.

2 in.

2 in.

2 in.

2 in.

2 in.

2 in.

4 in.

3 in.1 in.

32 in.

6x1 in.

TW 5 in.

8 in.

80134

CL&P

8134A

CL&P

WF 46

WF 47WF 30

WF 31

WF 26WF 1


SIGN

AT&TUGUF

CATVUGUF

CL&PUGUF

BIT. L.O.

BIT. L.O.

JPG-3 (I. P

IN)

No. 05491

BRIDGE

AQUARION W

ATER CO.

EXPOSED WATER M

AIN

Q 8 in.

8 in.

4 in. 8 in.

3 in.

3 in.

36 in.

2 in.

2 in.

2 in.

2 in.

2 in.

2 in.12 in

.

4 in.

3 in.1 in.

32 in.

6x1 in.

TW 5 in.

8 in.

80134

CL&P

8134A

CL&P

WF 46

WF 47WF 30

WF 31

WF 26WF 1


SIGN

AT&TUGUF

BIT. L.O.

BIT. L.O.

JPG-3 (I. P

IN)

No. 05491

BRIDGE

AQUARION W

ATER CO.

EXPOSED WATER M

AIN

130

E 748231.49

N 578938.37

STA 105+41.46

PC

106+00

105+00

- -

-

-

-

- -

- - -

- - - -

- - -

- - -

- - - -



OVER BYRAM RIVER

GREENWICH 56-299

GENERAL PLAN AND

STA 105+30.50

BEGIN BRIDGE

SKEW (TYP.)

22°56’ 45.09"

WINGWALL (TYP.)

REMOVE EXISTING

WINGWALL 1A

N 78°50’ 18.16 E

WINGWALL 1B

14’-0"

14’-0"

1’-10"

ABUTMENT

FACE OF

CURB LINE

LINE

CHORD

FACE OF ABUTMENT

WINGWALL 2B

WINGWALL 2A

ABUTMENT 1

BEARINGS

{ EXPANSION

ABUTMENT 2

{ FIXED BEARINGS,

SHOULDER

3’-0"

LANE

11’-0"

LANE

11’-0"

SHOULDER

3’-0"

1’-10"

1’-10"

B4B3B2B1 B5

(WOVEN GLASS FABRIC)

MEMBRANE WATERPROOFING

1" HMA S0.375 ON

2" HMA S0.5 ON

P.A.G.

�" / FT�" / FT

SLAB

8�" CONCRETE

} BAILIWICK ROAD

4 SPACES @ 6’-9" = 27’-0"

CROSS SECTIONSCALE: �" = 1’-0"

T.STRNAD/S.ERDAS

A. SESHADRI

GENERAL PLANSCALE: 1" = 10’

(VARIES)

2’-1�" TO 2’-8"

(VARIES)

4�" MAX.

RIVER

BYRAM

SH

LD

3’-0"

LA

NE

11’-0"

LA

NE

11’-0"

SH

LD

3’-0"

RA

DIA

L

1’-10"

(TYP.)

PAINTED TO COLOR BROWN

GALVANIZED & SHOP

BOX BEAM GUIDE RAIL,

} BAILIWICK ROAD

31’-8" TO 32’-4�"

INTERMEDIATE DIAPHRAGM (TYP.)

C12 x 20.7

LINE

CURB

1’-11�" TO 2’-7�"

(VARIES)

CONSTRUCTION

PROTECTED DURING

COMPANY) TO BE

(AQUARION WATER

EXISTING WATER MAIN

STA 105+89.60

END BRIDGE

STA 105+86.53

W.P. 2

STA 105+33.50

W.P. 1,

BRIDGE & FOOTINGS

CONCRETE ARCH

REMOVE EXISTING

(TYP.)

PAINTED TO COLOR BROWN

GALVANIZED & SHOP


(TYP.)

PROPOSED GRADE

SCALE: 1" = 10’

SOUTH ELEVATION

ABUTMENT 1

{ EXPANSION BEARINGS,

(ELEVATION VARIES)

ORDINARY HIGH WATERLINE

EL. TBD (TYP.)

BOTTOM OF FOOTING,

ABUTMENT 2

{ FIXED BEARINGS,53’-0"

ARCH BRIDGE & FOOTINGS

REMOVE EXIST. CONCRETE

(TYP.)

EL. 120.6|

ELEVATION-ALTERNATIVE 1

BEAM (TYP.)

WEATHERING STEEL

W21 X 101

TO COLOR BROWN (TYP.)

(HANDRAIL) ANODIZED

METAL BRIDGE RAIL

FORM LINERS (TYP.)

TREATMENT UTILIZING

WITH ARCHITECTURAL

2’-8" HIGH PARAPET& { BEAM B3

CHORD LINE

1’-3" APPROACH SLAB (TYP.)

3" HMA PAVEMENT OVER

CONCRETE DECK

BRIDGE WITH COMPOSITE

PROPOSED WEATHERING STEEL

(TYP.) (BY CL&P)

TO BE RELOCATED

EXIST. UTILITY POLE

8" CONCRETE PAVEMENT

2" HMA PAVEMENT OVER

EL. 130.82

LOW CHORD

CONCRETE DECK

BRIDGE WITH COMPOSITE

PROPOSED WEATHERING STEEL

EL. 130.8|

CHANNEL BED (SURVEY)

APPROX. EXIST.

UTILIZING FORMLINERS

ARCHITECTURAL TREATMENT

JOINT

1" EXPANSION

2

(T

YP.)

2’-8"

RECONSTRUCTION

FULL DEPTH HMA PAVEMENT

COLOR BROWN

ANODIZED TO

(HANDRAIL)

METAL BRIDGE RAIL

(TYP.)

ROADWAY

PROPOSED

ANODIZED TO COLOR BROWN

METAL BRIDGE RAIL (HANDRAIL)

GRANITE CURB

BORING B1)

EL. 124.1 (BASED ON

APPROX. TOP OF ROCK,

BORING B2)

EL. 123.5 (BASED ON


BORING B3)

EL. 121.4 (BASED ON


BORING LOCATION

DIRECTION OF TRAFFIC

LEGEND

B1

B2

B3


DESIGNER/DRAFTER:

CHECKED BY:


DRAWING TITLE:

PROJECT NO.

DRAWING NO.

SKETCH NO.



TOWN OF GREENWICH

SCALE AS NOTED

10/6/2011

BLOCK:

SIGNATURE/

DATE: APPROVED BY:


...\SB_MSH_056_0299_GPN-ALT1.dgnPlotted Date:

- -

-

-

-

- -

- - -

- - - -

- - -

- - -

- - - -



OVER BYRAM RIVER

GREENWICH 56-299

} BAILIWICK ROAD

36’-6"|

SCALE: �" = 1’-0"

SCALE: 1" = 10’

GENERAL PLAN ANDELEVATION-ALTERNATIVE 2

T.STRNAD/S.ERDAS

A.SESHADRI

38’-0"|

9"

3"

LANE

11’-0"

LANE

11’-0"

�"/FT �"/FT

3"

1’-6" 9"

(TYP.)

REINFORCEMENT

DRILL AND GROUT

(TYP.)

FACING

MASONRY

(TYP.)

WALL

SPANDREL

P.A.G.

ROAD

} BAILIWICK

HEADWALL 1

WINGWALL 3A

2’-6"

LINE

CURB

LINE

CURB

HEADWALL 2

WINGWALL 3BTO COLOR BROWN (TYP.)

GALVANIZED & SHOP PAINTED


RIVER

BYRAM

SCALE: 1" = 10’

GENERAL PLAN

WINGWALL 1B

20’-9�"

33’-8�"

WINGWALL 2B

15’-11"

SPANDREL WALL (ELEVATION VARIES)

WATERLINE

ORDINARY HIGH

EL. TBD (TYP.)

BOTTOM OF FOOTING,

PROPOSED GRADE

(TYP.)

EL. 120.61

SOUTH ELEVATION

PROPOSED ROADWAY

(TYP.)

STANDARD RIPRAPEL. TBD

CUT-OFF WALL

(TYP.)

MASONRY FACING

TO COLOR BROWN (TYP.)

GALVANIZED & SHOP PAINTED


(VARIES)

3’-0" MIN.

SHLD

3’-0"7"

CURBING

8"X16" SLOPED GRANITE

SLAB (TYP.)

1’-0" MOMENT

(THICKNESS VARIES)

GRANULAR FILL

CROSS SECTION

& EXTRADOS

ARCH INTRADOS

REPAIR EXISTING

(TYP.)

ANODIZED TO COLOR BROWN

METAL BRIDGE RAIL (HANDRAIL)

CURBING

6" GRANITE

PAVEMENT

8" CONCRETE

VARIES)

ARCH SLAB (THICKNESS

WINGWALL 1B

WINGWALL 1AWINGWALL 2A

GRANITE CURBING

8"X16" SLOPED

WINGWALL 2B

RA

DIA

L

14’-0"

CURBING

6" GRANITE

(BY CL&P) (TYP.)

TO BE RELOCATED

EXIST. UTILITY POLE

OVER FLOW

TO COLOR BROWN

(HANDRAIL) ANODIZED

METAL BRIDGE RAIL

HEADWALL 2

21’-8"

TO COLOR BROWN

(HANDRAIL) ANODIZED

METAL BRIDGE RAIL

CHANNEL BED (SURVEY)

APPROX. EXIST.

ARCH INTRADOS & EXTRADOS

REPAIR EXISTING

(TYP.)

EL. 127.4|

EL. 130.8|

CONSTRUCTION

PROTECTED DURING

COMPANY) TO BE

(AQUARION WATER

EXISTING WATER MAIN

3

PAVERS (TYP.)

3" CONCRETE BLOCK

2’-8"

SHLD

3’-0" MIN.

2’-8"

RA

DIA

L

11’-0"

RA

DIA

L

11’-0"

2’-3"

MIN.

14’-0"

B1

B2

B3

SH

LD

3’-0"

SH

LD

3’-0"

MIN.

BL

OC

K

PA

VE

RS

3’-0"

MIN.

CO

NC

RE

TE

(TYP.)

WITH CONCRETE WINGWALLS

WINGWALLS & REPLACE

REMOVE EXISTING MASONRY

PAVEMENT

MOMENT SLAB & INSTALL CONCRETE

REPLACE SPANDREL WALL, CONSTRUCT

& REPAIR ARCH INTRADOS & EXTRADOS.

REMOVE FILL ABOVE EXISTING ARCH

ARCH BRIDGE NO. 05491

EXISTING CONCRETE

PAVEMENT

LIMITS OF 8" CONCRETE

104+00

TO STA.

BORING B1)

EL. 124.1 (BASED ON


BORING B2)

EL. 123.5 (BASED ON


BORING B3)

EL. 121.4 (BASED ON


INV. EL. 126.9

RELIEF CULVERTS

(2)-9’-0" X 4’-0" CONC.

BORING LOCATION

DIRECTION OF TRAFFIC

LEGEND

STRUCTURE STUDY REPORT

DESIGNER/DRAFTER:

CHECKED BY:


DRAWING TITLE:

PROJECT NO.

DRAWING NO.

SKETCH NO.



TOWN OF GREENWICH

SCALE AS NOTED

10/6/2011

BLOCK:

SIGNATURE/

DATE: APPROVED BY:


...\SB_MSH_056_0299_GPN-ALT2.dgnPlotted Date:

CULVERTS. BRIDGE NO. TBD

(2) 9’-0" X 4’-0" CONCRETE RELIEF

1’-6"

E 748231.49

N 578938.37

STA 105+41.46

PC

106+00

105+00

1301 in.

TW 10/16 i

n.

Q 8 in.

4 in. 8 in.

3 in.

3 in.

36 in.

2 in.

2 in.

2 in.

2 in.

2 in.

2 in.

4 in.

3 in.1 in.

32 in.

6x1 in.

TW 5 in.

8 in.

80134

CL&P

8134A

CL&P

WF 46

WF 47WF 30

WF 31

WF 26WF 1


SIGN

AT&TUGUF

CATVUGUF

CL&PUGUF

BIT. L.O.

BIT. L.O.

JPG-3 (I. P

IN)

No. 05491

BRIDGE

AQUARION W

ATER CO.

EXPOSED WATER M

AIN





Appendix D

Construction

Schedule

OPERATION DATE

Advertisement 1/1/2014

Bid opening 2/1/2014

Award contract 3/15/2014

Notice to proceed 4/1/2014

Mobilization 4/1/2014

Install detour plan & close bridge to through traffic 4/15/2014

Temporary/permanent utility relocation

Clearing & grubbing & install sed. control system

Install debris shield, excavate & remove existing arch bridge

Install temporary earth retaining system

Complete structure excavation

Remove existing arch bridge footings & wingwalls

Construct abutment & wingwall footings

Construct abutment and wingwall stems

Backfill behind abutments & wingwalls and remove

temporary earth retaining system

Install bearings and erect steel beams

Construct bridge deck & parapets

Construct approach slabs

Install waterproofing membrane & bituminous wearing

surface on bridge deck/approach slab

Complete earth excavation & install concrete pavement at

roadway approaches

Complete drainage and approach roadway work

Install bridge rail and approach guiderails

Loam & seed disturbed areas

Open bridge to thru traffic 10/31/2014

0 30 60 90 120 150 180 210

September

CONSTRUCTION SCHEDULE

REHABILITATION OF BRIDGE NO. 05491

TOWN OF GREENWICH, CT

STATE PROJECT No. 56-299

ALTERNATIVE 1: BRIDGE REPLACEMENT

October November


December

2014

January February March April May June July August

OPERATION DATE

Advertisement 1/1/2014

Bid opening 2/1/2014

Award contract 3/15/2014

Notice to proceed 4/1/2014

Mobilization 4/1/2014

Install detour plan & close bridge to through traffic 4/15/2014

Temporary/permanent utility relocation

Clearing & grubbing & install sed. control system

Install work platforms below existing arch bridge & remove

fill material above the arch

Perform repairs to existing arch intrados/extrados

Install temporary earth retaining system

Complete structure excavation

Remove existing wingwalls

Install new box culverts

Construct new wingwall footings

Construct culvert headwalls, wingwall stems & spandrel walls

Install moment slab over arch bridge

Backfill behind/above wingwalls, culverts & existing arch

bridge

Install masonry facing

Complete earth excavation & install concrete pavement

Complete drainage and approach roadway work

Install bridge rail and approach guiderails

Loam & seed disturbed areas

Open bridge to thru traffic 10/31/2014

0 30 60 90 120 150 180 210

September October November December

ALTERNATIVE 2: BRIDGE REHABILITATION WITH ADDITION OF RELIEF CULVERTS

2014

January February March April May June July August

CONSTRUCTION SCHEDULE

REHABILITATION OF BRIDGE NO. 05491


TOWN OF GREENWICH, CT

STATE PROJECT No. 56-299





Appendix E

Cost Estimates

ITEM QUANTITY UNIT UNIT PRICE AMOUNT

A. Roadway Items

Earth excavation 800 CY $40.00 $32,000

8" Concrete Pavement 80 CY $750.00 $60,000

HMA Pavement 575 TON $120.00 $69,000

Subbase 400 CY $50.00 $20,000

Granite Curbing 420 LF $45.00 $18,900

Approach Guide Railing 150 LF $25.00 $3,750

Approach Guide Railing: End Anchorage 4 EA $1,250.00 $5,000

Approach Guide Railing: Bridge Attachments 4 EA $3,000.00 $12,000

Striping 425 LF $1.00 $425

Roadway Drainage 1 LS $23,000.00 $23,000

Sedimentation Control System 300 LF $6.00 $1,800

Construction Field Office, Small 9 MO $1,800.00 $16,200

Sub Total $262,075

B. Structure Items

Structure Excavation - Earth (Complete) 1,063 CY $35.00 $37,201

Cofferdam & Dewatering 140 LF $325.00 $45,500

Temporary Earth Retaining System 2,249 SF $40.00 $89,960

Removal of Superstructure 1,267 SF $50.00 $63,350

Removal of Masonry 229 CY $150.00 $34,422

Structural Steel 33,579 LBS $3.00 $100,737

Class F Concrete (Superstructure) 131 CY $850.00 $111,328

Class A Concrete (Substructure) 448 CY $750.00 $336,365

Deformed Steel Bars (Epoxy Coated) 32,750.00 LBS $1.60 $52,400

Deformed Steel Bars 29,160.00 LBS $1.40 $40,824

Steel Laminated Elastomeric Bearings 10 EA. $900.00 $9,000

Perevious Structure Backfill 433 CY $50.00 $21,674

Membrane Waterproofing (Woven Glass Fabric) 283 SY $30.00 $8,493

HMA Wearing Surface 31 TON $120.00 $3,717

Concrete Form Liners 2,593 SF $20.00 $51,854

Metal Bridge (Handrail) 160 LF $150.00 $24,000

Asphaltic Plug Expansion Joint System 56 LF $110.00 $6,160

Sub Total $864,325

C. Environmental Compliance Items

Estimated Cost 1 EST $20,000.00 $20,000

D. Traffic Items

Traffic Person (Municipal Police Officer) 32 HR $100.00 $3,200

Construction Signing 300 SF $25.00 $7,500

Temporary Precast Concrete Barrier Curbs 80 LF $40.00 $3,200

Construction Barricade - Type III 8 EA $140.00 $1,120

Sub Total $15,020

E. Minor Items (20% of Roadway Items) 20% $52,415

F. Lump Sum Items (Based on percentages of A-E)

Cleaning & Grubbing 2% $24,277

M&P of Traffic 4% $48,553

Mobilization 7.5% $91,038

Construction Staking 1% $12,138

CONSTRUCTION TOTAL $1,389,841

SAY $1,390,000

G. Incidentals (25%) & Contingencies (10%) 35% $486,444

TOTAL ESTIMATED COST (Year 2011) $1,876,285

Say $1,880,000

Alternative 1: Bridge Replacement

PROPOSAL ESTIMATE




State Project No. 56-299

ITEM QUANTITY UNIT UNIT PRICE AMOUNT

A. Roadway Items

Earth excavation 750 CY $40.00 $30,000

8" Concrete Pavement 130 CY $750.00 $97,500

HMA Pavement 520 TON $120.00 $62,400

Subbase 500 CY $50.00 $25,000

Granite Curbing 460 LF $45.00 $20,700

Approach Guide Railing 150 LF $25.00 $3,750

Approach Guide Railing: End Anchorage 4 EA $1,250.00 $5,000

Approach Guide Railing: Bridge Attachments 4 EA $3,000.00 $12,000

Striping 425 LF $1.00 $425

Roadway Drainage 1 LS $20,000.00 $20,000

Sedimentation Control System 300 LF $6.00 $1,800

Construction Field Office, Small 9 MO $1,800.00 $16,200

Sub Total $276,775

B. Structure Items

Structure Excavation - Earth (Complete) 1,387 CY $35.00 $48,541

Cofferdam & Dewatering 80 LF $325.00 $26,000

Temporary Earth Retaining System 2,275 SF $40.00 $91,000

Removal of Masonry 65 CY $150.00 $9,711

Concrete Arch Repairs (Intrados & Extrados) 7 CY $3,000.00 $22,222

Class A Concrete (Spandrel walls/Parapets/Wingwalls/Headwalls/Moment Slab) 378 CY $750.00 $283,135

Deformed Steel Bars 24,540 LBS $1.40 $34,356

Perevious Structure Backfill 411 CY $45.00 $18,480

Granular Fill 125 CY $45.00 $5,610

Masonry Facing 2,370 SF $80.00 $189,618

Metal Bridge (Handrail) 200 LF $150.00 $30,000

Concrete Block Pavers 350 SF $35.00 $12,250

9' x 4' Concrete Box Culvert 80 LF $850.00 $68,000

Sub Total $838,923

C. Environmental Compliance Items

Estimated Cost 1 EST $20,000.00 $20,000

D. Traffic Items

Traffic Person (Municipal Police Officer) 32 HR $100.00 $3,200

Construction Signing 300 SF $25.00 $7,500

Temporary Precast Concrete Barrier Curbs 80 LF $40.00 $3,200

Construction Barricades - Type III 8 EA $140.00 $1,120

Sub Total $15,020

E. Minor Items (20% of Roadway Items) 20% $55,355

F. Lump Sum Items (Based on percentages of A-E)

Cleaning & Grubbing 2% $23,721

M&P of Traffic 4% $47,443

Mobilization 7.5% $88,956

Construction Staking 1% $3,472

CONSTRUCTION TOTAL $1,349,665

SAY $1,350,000

G. Incidentals (25%) & Contingencies (10%) 35% $472,383

ESTIMATED CONSTRUCTION COST (Year 2011) $1,822,048

Say $1,830,000

State Project No. 56-299



PROPOSAL ESTIMATE


Alternative 2: Bridge Rehabilitation with Addition of Relief Culverts

state project no. 56-299 town project no. 06-44 … · safely carry the hl-93 legal load. design...

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