The Analysis Based On FLAC3D Of The Shanghai Mansion Foundation Pit Supporting Stability

With the modernization of the city continued rapid development of surface space gradually been unable to satisfy the requirements of the production of human life,becoming more and more crowded, more and more confusing, this time, human beings must find new Available the space, with its hidden underground space,reliability, as well as many advantages so that people began to increase the utilization of underground space. The rapid development of underground space is a strong impetus to the development of the excavation, the development direction of the deep excavation into a larger scale and deeper depths.Although it is only a safety aid during pit construction, but unreasonable supporting programs and systems able to lead to the failure of the whole project and even lead to more security problems, so as to be safe and reliable premise, in under different geological conditions, as far as possible to choose more cost-effective support plan to facilitate simple construction we now need to become a research subject. And now supporting various forms of complex combinations as a way to support both the mainstream in different sections of the safe and effective support, but also a concrete analysis of concrete block, greatly protect the safe. according to Urumqi City Shanghai Mansion Foundation pit example,describes the row of piles and prestressed bolting support and little effective model simulation to prove their superiority. The contents of this article are:(1) summarizes the characteristics of row and prestressed piles and anchor support method,commonly used design methods, application status;(2) according to the "Shanghai Building Geotechnical Investigation Report" design a reasonable complex type excavation program verification;(3) application software FLAC3 D established pit model, excavation support and loading to simulate damage from excavation deformation characteristics and failure modes of loading and other aspects of pile stability and mechanical properties of anchor retaining way;(4) respectively,excavation and support each stage of the simulation to demonstrate the safety and reliability of each stage of support.The main conclusions of this article are:(1) the design of pile- anchor supporting programs can effectively control the displacement of the pit wall in a safe range; mode(2) prestressed bolt passing through the surface layer of the soil displacement only a range of memory in effective control;(3) prestressed anchor support ways that may affect the position of potential sliding surface so that the body may have two potential soil sliding surface;(4) row of prestressed anchor pile bolt failure mode and failure mode support of non-prestressing are not the same;(5) the prestressed anchor body can effectively control soil plastic zone, because the compressive stress generated area;(6) prestressed soil anchors soil nail soldier pile retaining safety factor than either one alone support higher protection;(7) during the simulation FLAC3 D should note the importance of the assignment and a contact surface;(8) analog data presented herein pre stability analysis of stress anchor plus row of piles is reasonably reliable.