The Analytical Study Of Deep Foundation Strutted Calculation Methode In Tianjin District.

The excavation of foundation pits is an old and traditional topic in foundation and subterranean engineering. It is a very practical problem in geotechnical engineering. It is closely related to the soil and water condition, the main structure type and its construction method and the surrounding environment, etc. The calculation method of the strutted structure is especially important in the engineering of deep foundation pits. Due to the complexity and regionality of the soil itself, selecting the calculation parameters in the strutted structure calculation is still the key part of the current foundation pits analyzing. There are still many defects in the current research method.Based on vast amount of engineering documentations, this document analyzes the physical mechanics of the surface layer of soil in Tianjin area and the practicability of the elastic-resistance method in the calculation of strutted structure in deep foundation pits. Out of representative site testing results, this document focuses on the calculation of deep foundation pit struts used in the cement-soil gravity retaining walls systems, the drill-and-pour cantilever pile systems and the anchored pile-row systems. These analysis and research show that the elastic-resistance method can take in to consideration different edge conditions and complicated construction factors and also reflect the interaction between soil and the structure, thus can be very suitable for the calculation of the internal forces and the displacements within the strutted structure. This document also applies the elastic-resistance method in strut analysis under the direct-shear/solidification/instant-shear soil/water combined calculation assumption, the direct-shear/solidification/instant-shear soil/water independent calculation assumption and the direct-shear/instant-shear soil/water combined calculation assumption. By comparison to real site testing results, this document concludes that the direct-shear/solidification/instant-shear soil/water combined calculation assumption is the most accurate design and calculation method in the struts system analysis in deep foundation pit construction.