Calculation And Analysis About Deep Foundation Pit Supporting And Dewatering In Loess Area

With the rapid development of city civil enginerring,building’s density is increasing very rapiddy.In order to save the limited land resources,the development and utilization of underground space becomes a important construction problems.Such as Large underground municipal facilities,subway stations,subway lines,this underground business is becoming a large number of constructions.The basement layer is increasing gradually,and the area of deep foundation pit engineering is more and more big, depth is larger and larger.The geological conditions and foundation pit surrounding environment variability is very complicated,so deep foundation pit supporting and dewatering has become an important subject in geotechnical engineering research.After reading the relevant research literatures and documentations systematically, based on the study of the deep foundation pit at home and abroad, in this paper, combined with an engineering example,deep foundation pit supportings and dewaterings in loess area has been calculated and analyzed, deep foundation pit supporting was discussed according to the structure types of classification and selection principle,and the loess soil engineering properties were analysised systematically on the basis of the selected support structure characteristics and their application conditions.At the same time, in this paper, taking Beijing Hualian Group Xi’an shopping mall foundation pit supporting and dewatering as a project example,for the forced deformation of the bolt(anchor), through the study of the pull-out test of bolt(anchor) and axial force test, deep foundation pit supporting in loess area is obtained in the regularity of stress deformation behavior of the bolt(anchor). For the combination form of bolt(anchor) waist beam, steel(channel), by discussing the structure calculation model, the material strength and deformation are calculated, obtained in the loess area, deep foundation pit supporting channel steel applied to bolt(anchor) waist beam the calculation results and the principle of model selection.On the basis of actual precipitation of foundation pit dewatering,comprehensive permeability coefficient k value of the foundation soil aquifer was reverse calculated,the comprehensive permeability coefficient k experience value was obtained of the foundation soil aquifer of the construction site. The above research results are available for the construction of similar engineering conditions in loess ground reference.