Monitoring Lateral Earth Pressures and Movements of Cut Retaining Walls

Details

• Creators:
  Marr, W Allen ; DiMaggio, Jerry A. ; Ross, Dori ; Hawkes, Martin ; Gokyer, Seda
• Corporate Creators:
  Geocomp Corporation
• Corporate Contributors:
  Wisconsin. Dept. of Transportation. Research and Library Unit ; United States. Department of Transportation. Federal Highway Administration
• Subject/TRT Terms:
  Cut Retaining Walls Earth Pressure Ground Settlement Lateral Earth Pressure Limit State Design Mathematical Prediction Monitoring Performance Measurement Retaining Walls Service Limit States Soil Structure Interaction Strength Limit States Structural Design Wall Movement

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• Publication/ Report Number:
  WHRP 0092-17-08
• Resource Type:
  Tech Report
• Geographical Coverage:
  United States
• Edition:
  Final report, June 2017 – October 2019
• Corporate Publisher:
  Wisconsin. Dept. of Transportation. Research and Library Unit
• Abstract:
  The design and performance of retaining walls requires accurate estimates of the lateral earth pressures for strength limit states and service limit states. Several design methods are available and are used to predict the lateral earth pressures acting on the wall as well as the lateral and vertical wall movements of the wall and of the soil behind the wall. The magnitude of the lateral earth pressure is dependent on the lateral deformation of the wall and the deformation is dependent on the lateral earth pressure. This dependence creates a complex soil-structure interaction problem. Wisconsin Department of Transportation (WisDOT) developed this research project to evaluate how to best predict lateral earth pressures and wall movements for use in their future cut wall projects. The research aims to develop guidance to accurately predict horizontal and vertical movements of cut retaining walls, obtain data for calibration of specific design methodologies, and provide recommendations for limit states that can be used to control wall performance. Two cut retaining walls were instrumented and remotely monitored over a 15-month time period. During this time period automated readings were collected to obtain measurements of the wall displacements, strains in the wall’s structural elements, and pore pressures in the retained soil. Comparisons were made by the research team for the cut retaining walls studied to successfully compare actual measured performance of the walls with the predicted design performance using several commonly used design methods. Based on the results of this study, the research team has provided several recommendations for WisDOT to consider for its future wall design practice. These recommendations include: • Designers should include all applicable load cases to ensure that worst case loading, or a combination of loading is addressed. WisDOT should also consider developing standard details for protection against pore water pressure buildup and ground freezing behind the wall. • Designers should consider both undrained and drained cases for each wall design to cover various possibilities that can develop in the field during construction and post construction. • Designers using the PY-WALL method should obtain soil parameters for actual site conditions using a pressure meter or lab testing on undisturbed samples rather than using the p-y curves internally generated by the software. • WisDOT should consider requiring performance testing of a representative number of anchors in its specifications to reduce uncertainty in the actual anchor lock-off loads. • WisDOT should consider requiring more detailed documentation by contractors of their sequence of work and the dates work is performed for retaining wall construction. • For unusual cases, and cases where poor wall performance could create significant risks and costs, strong consideration should be given to instrumenting and monitoring representative wall sections. • For cut walls where the zone of influence of the construction might include existing utilities and/or buildings that could be impacted by ground settlement, methods other than SPW911 and PW-WALL should be used to predict ground settlements as neither of these programs calculate ground settlement behind the wall.
• Format:
  PDF
• Funding:
  WHRP 0092-17-08
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:91a464d593e6d5f72b8277b758cb54cd308857bb3358aa26dd8a3ff9d567d3a3
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/56895/dot_56895_DS1.pdf
• File Type:
  [PDF - 1.80 MB ]