Chengdu Some Deep Foundation Pit Supporting Scheme Optimization Research

With the rapid rise of China's economy,accelerating the pace of urbanization,urban deep excavation is also increasing.In the actual construction process,or if the building size and functional requirements of the new changes,or differences in site geological conditions and exploration results is large,it will cause changes to the design of the excavation.How to consider the actual construction under the current conditions,the proposed best supporting structure of the new program,has important practical significance.Chengdu,a deep excavation construction is such projects in a typical case.In order to meet user demand for the new proposed project shall continue to deepen down at the bottom of the original design of the excavation pit about three meters.However,at this envelope pile has been largely completed,the local area also completed the construction of the first anchor row and the second row.How to make the best design in the original design basis,it is a key technical issues need further careful study.To solve this engineering problem,select No.1-21 supporting by enclosing piles area(referred to as the segment AB)to carry out optimization of the new program.For this section excavation of the original design,and taking into account paragraph increases the maximum depth of the excavation,and has completed the actual situation of the first row and the second row of anchor construction,etc.This paper summarizes the excavation works development status,determined using the recommended specification Lizheng and large commercial software ABAQUS finite element software are two ways of optimizing supporting structure research ideas.According to deep foundation supporting structural design principle,we developed 10 kinds of support plan.respectively,preclude the use of positive management and ABAQUS finite element software to develop these 10 kinds of programs all the calculations and related engineering specifications based on the calculation results were analyzed,and finally proposes the optimal design for this excavations.