Application And Research Of Pile-anchor Supporting Structure In A Foundation Pit Project

Since the 21st century,our country has entered into the world's highest overall economic level,and large amount of people into the city center,continuously increasing scale of urban construction.At the same time,many development problem,running to be solved,such as,the spike in the number of urban population living pressure,the increasing traffic pressure with motor vehicle.In order to relieve these increasingly obvious contradictions,the utilization of urban underground space,has become one of the focus of city construction.The towering buildings of booming development,on one handrelieve the contradictions of the needs of people living,on the other hand also contribute to expand the utilization of underground space.the booming utilization of urban underground space,so that makes underground engineering excavation and supporting of related theory and technology of exploration more and more importance to people.Based on a foundation pit supporting project in Hunan area,this paper discusses the necessity of pile anchor combined support,test and verify the reliability of the supporting design with the method of numerical simulation in combination with engineering monitoring,and has a certain theoretical and practical significance,providing a reference for similar excavation engineering in the region.Get the following main conclusions:?1?This paper systematically expounds the basic structure and working mechanism of the retaining pile support and prestressed anchor,analyses the necessity of pile anchor support,sums up the pile anchor supporting structure design theory of common analysis summary at the same time.?2?Combined with the special environment of the foundation pit,this paper compares and analyses the support forms of pile-anchor cable,pile-internal support and diaphragm wall from three aspects of construction period,safety and economy,and determines that the support form of piles-anchor cable will be adopted in the foundation pit project.?3?FLAC^3Dsimulation results show that:?1?in the course of earthwork,maximum horizontal displacement occurred in the foundation pit excavation near the central position;?2?in the course of earthwork,anchor cable free of the axial force remains unchanged,the anchoring with the surrounding soil of side friction force,pass the present along the cable length direction gradually less trend;?3?the maximum displacement of foundation pit is about 6.7 mm,the pile anchor supporting parameters can meet the control of deformation.?4?The field monitoring data show that on the one hand,as a result similar to the results of numerical simulation,on the other hand shows that pile plus anchor rope support parameter design is feasible and deformation has been effectively controlled.