Abstract:

The supporting schemes of deep foundation pit of Longdongzhuang Station on Line R3 of Jinan Metro closely adjacent to a highrise building are numerically simulated; and then the foundation pit stability and supporting piles deformation under different supporting schemes are analyzed. Finally, a multiple attribute decisionmaking model is established and the optimum supporting scheme is selected considering safety, economy, construction schedule and feasibility of every supporting scheme. The results indicate that: 1) In view of safety, the lateral displacement of supporting pile towards internal foundation pit is too large to keep safe under original supporting scheme. 2) The horizontal displacement of supporting pile decreases; but the construction difficulty increases under doublerow piles supporting scheme. 3) The horizontal displacement of pile closed to highrise structure is allowable and the deformation of supporting pile close to highrise building can be controlled under pile+anchor bolt supporting scheme. 4) The horizontal displacement of supporting pile close to highrise building is very small; but the construction cost is much higher under improved pile+shaped steel supporting scheme. 5) By establishing and using the multiple attribute decisionmaking model, the optimum supporting scheme of pile + anchor bolt is decided.

Key words: asymmetric load, deep foundation pit, supporting scheme, numerical simulation, multiple attribute decisionmaking model