A generalised approach for the analysis of diaphragm wall-supported deep excavation present in the vicinity of the existing buried tunnel

The study provides a generalised approach for the estimation of earth pressure forces on the excavation support system using a diaphragm wall, taking into consideration the presence of a cavity in the retained ground as well as load transferred to the supporting wall due to the self-weight of the buried pipe or utility tunnel, as well as the overburden load of the soil. The theoretical perspective of the proposed solution is based on Rankine’s earth pressure theory and Spangler’s solution, based on Modified Boussinesq’s approach. A parametric study is then performed, taking into account different buried pipe or utility tunnel diameters located very near the 15 m deep excavation support system in the upper, middle, or lower zone. Numerical analysis using STAADPro is involved to estimate the deformation as well as the shear and bending moment in the diaphragm wall by assuming its cantilever action, and the results are presented to analyse and discuss the influence of the presence of a buried pipe or utility tunnel very near the deep excavation support system using a diaphragm wall.