University of New Hampshire
Mentor: Dr. Majid Ghayoomi
Experimental and Theoretical Evaluation of Internal Loads in Underground Retaining Structures
Underground structures are an important part of civil infrastructure in modern urban areas to address the growing need for space. They are used in a wide range of engineering applications including underground parking lots, underground transportation systems, and underground storage facilities. These structures typically require soil excavation from the ground surface. Thus, stability of the excavated ground is a major challenge in the design and construction process. Bracing approaches are implemented in the current state-of-practice to ensure the safety of the excavation. The common “Braced Excavation” system involves retaining walls on both sides held in place using internal struts. These struts are designed considering the strength of the material (i.e. soil and steel) and soil lateral pressure. However, due to uncertainties involved in the material properties and estimation of the soil pressure, engineers implement factors of safety in their design calculations.
The goal of the project is to find the internal strut loads of a model braced excavation using centrifuge physical modeling. A model braced excavation system will designed based on the theoretical method of Peck’s pressure distribution envelopes. Then, a scaled physical model will be employed to simulate the model’s system using centrifuge modeling. The measured and calculated forces will be compared and the differences will be identified to see how the theoretical loads compare to the loads measured in the real-world.