Rehabilitation of

Griggstown Causeway

Catherine Miguelez

Site Engineer

Matthew Milgrom

Geotechnical Engineer

Asha Mahmood

AutoCAD Production Engineer

Jerard Richards

Structural Engineer

Section 1: Bridge Design Project overview                                                       2

Section 1.1: Proposed Bridge Location                                                                                      2

Section 1.2: Project Description                                                                                                 2

Section 1.3: Site plan, and bridge characteristic and constraints                                                3

Section 2: Environmental Impact Analysis                                                      4

Section 3: Utilities                                                                                              4

Section 3.1: Bridge Lighting                                                                                                      4

Section 3.2: Water Main/Utilities                                                                                               4

Section 3.3: Storm Water Analysis                                                                                             4

Section 4: Traffic Analysis                                                                                                             4

Section 4.1: Roadway Layout                                                                                                    4

Section 4.2: Typical Roadway Cross Section                                                                             5

Section 5: Bridge Elevation and Plan                                                                                            5

Section 5.1: Plans and elevations                                                                                                5

Section 5.2: Preliminary design and design alternatives                                                             5

Section 6: AutoCAD Design                                                                                                           5

Section 7: Final Design                                                                                                                   6

Section 8: Calculations                                                                                                                    6

Section 8.1: Superstructure Calculations                                                                                    6

Section 8.2: Substructure Calculations                                                          6

Section 9: Cost Analysis                                                                                                                  6

Section 9.1: Construction Sequencing                                                                                        7

Section 9.2: Cost analysis of alternative superstructures and substructures                               7

References                                                                                                                                       8

Acknowledgments                                                                                                                           8

Appendix                                                                                                                                         8

Section 1: Bridge Design Project overview

Section 1.1: Proposed Bridge Location

Originally being built in 1978, many residents of Somerset County found the Griggstown

bridge to be a part of that area’s history. The one-lane bridge, which was restored in 2006 has since been used by many who are looking to visit the adjacent Princeton Highlands. Since its restoration, many have found that the original make of the bridge has yet to update to meet the needs of a thriving society. Based on a report done in 2017, the bridge saw a general usage of 2,150 vehicles. After a full inspection the bridge was given a sufficiency rating of 69.3% with an estimated cost of $3,000 for necessary upkeeps. As many more people find themselves using cars as a means of travel, the town of Griggstown feels the need to give a much needed update to the bridge. Given its natural setting, Bridge Solutions Co. is using all means necessary in providing an aesthetically pleasing bridge that will last for years to come.

Figure 1: Original Image of Griggstown Bridge Construction

Section 1.2: Project Description

The current dimensions of the bridge were made to support one way traffic across the Millstone River. The bridge had a deck width of 16.1 feet with 13.5 feet of roadway reserved between the curbing. Being that the bridge was not protected by the National Register of Historic Places, the team was allowed to take creative liberty in the design of the bridge. The current project involved the expansion of the current bridge while also doing a complete replacement of the superstructure and substructure that was pre existing. The new guidelines set forth included adding a second lane for optimal traffic flow, and creating shoulder lanes on both ends. Using the edition of these changes, while also considering the length of the barriers, the new bridge would extend substantially to a deck totaling at 44 feet in width. The length will remain at what it is currently, based on a Google Maps measurement, of 150 feet.

Figure 2: Current Bridge (Blue) and Proposed Bridge (Red)

Section 1.3: Site plan, and bridge characteristic and constraints

As one refers to figure 2, the current allotted spacing requires excavation of some surrounding area. This is required to allow enough space for the abutments. Throughout its life, the bridge has used a wall pier type; however, the extension of the bridge requires the uprooting of the existing natural region. In order to leave the terrain as undisturbed as possible, a tee type pier would be used in the redesign. Having a slimer base which grows to a wider structure, the tee type would allow for less space occupancy, thereby conserving the area. A change in the abutment type will not be necessary as the erosion caused by the Millstone River requires the use of a slope abutment. These will be accompanied by wing walls on both ends in order to avoid the water flow from corroding away at the exterior too viciously.

Once the extension of the bridge is completed, the deck will be the main focus until the project’s completion. Currently, the bridge has barricades of DOT standard steel beams along roadside curbing. This takes up about six inches on both sides of the bridge. Hanging at the very end of either side is oxidized steel, fashioned in a truss pattern. This is meant as an aesthetic feature to the bridge; therefore, it is not necessarily meant to support any structure or act as a safety measure. The curbing and exterior trusses will all be removed as the project progresses. When replacing the barrier, the new barrier will have a width of two feet. The concrete sections will be purchased from an outside company in sections of eight feet. Their purpose will act as both a protective barrier for cars as well as an aesthetically pleasing addition to the wider bridge. Spanning eight feet inward from the barriers, the bridge will have two shoulder lanes marked by six inch white paint. In order to appeal to a larger demographic, the bridge will have signage on both ends as a way of showing that the shoulders can also be used as bike lanes. Each lane of vehicular traffic will span 12 feet in width with a double yellow line marking the center. These yellow lines will continue onto the main road, connecting bridge traffic back to the mainland.

Figure 3: DECO Bridge Barrier in 8 feet Sections

Section 2: Environmental Impact Analysis

Based on the most common google searches related to Griggstown Causeway, most searches related to the bridge are quick to follow with “closure”. Although one of the most convenient ways of crossing the Millstone River, this bridge often is met with many closures. Whether it be the result of a rainstorm or closure for maintenance work, members of the community go frustrated with no proposed solution in their site.

Section 3: Utilities

Section 3.1: Bridge Lighting

• AASHTO requires yadadyada

Section 3.2: Water Main/Utilities

Section 3.3: Storm Water Analysis

Section 4: Traffic Analysis

Section 4.1: Roadway Layout

The

In 2018, the Somerset County freeholders decided to donate $75, 065 to WSP so that they could perform a study on the traffic pattern of the Griggstown Causeway. This was meant to assure the townspeople that the issue of traffic flow on this bridge was being put as something of importance. By 2020, WSP has not released the study they have been conducting as it was determined that further research had to be considered.

Section 4.2: Typical Roadway Cross Section

Current Roadway Cross Section

Proposed Roadway Cross Section

Section 5: Bridge Elevation and Plan

Section 5.1: Plans and elevations

Section 5.2: Preliminary design and design alternatives

Section 6: AutoCAD Design

15. Typical Girder Details (CAD)
16. Concrete Deck Details (CAD)
17. Pier Dimensions -Pier Footings – Pier Reinforcement – Pier Footings Reinforcement

18.Abutment Walls (CAD)– Abutment Footings – Slab Reinforcement

19. Bearing Details

Section 7: Final Design

6.Final design for superstructure slab.

7.Final design for superstructure girders

8.Final design for piers and abutments.

9.Final design for foundations and bearings.

10.The constructor’s view of design. Construction schemes

Section 8: Calculations

Section 8.1: Superstructure Calculations

Girder Calculations

Deck Calculations

Bearing Calculations

Design Calculations

Section 8.2: Substructure Calculations

Abutment Foundation Calculations

Abutment Pile Calculation

Abutment Reinforcement Calculation

Pier Foundation Calculations

Pier Pile Calculation

PierReinforcement Calculation

Section 9: Cost Analysis

Section 9.1: Construction Sequencing

Section 9.2: Cost analysis of alternative superstructures and substructures

References

https://www.mycentraljersey.com/story/news/local/somerset-county/2019/07/12/somerset-county-studying-improvements-griggstown-causeway-area/1705268001/

https://48barriers.com/products/8-ft-deco-barrier/

https://bridgereports.com/1368229

Acknowledgments

This research was performed under the jurisdiction of Group A. The project was the responsibility of the members in relation to the  registered course of CE495-451. Professor Giri provided substantial information throughout the course in order to aid in the authenticity of the report. He availed himself to the students with a consistent contacting  platform that allowed any questions to be answered within 24 hours. By making himself available, the project was able to run smoothly and meet all necessary requirements.

Catherine Miguelez was the site engineer of the group. Using her background from creating bids for contracting internships, she provided this to the work in place. Her tasks included

Appendix