Stability Analysis On The Deep Foundation Pit For The Xiaotianzhu Station Of Chengdu Metro

With the development of Chengdu's urban fast rail traffic system, there will be active effect for Chengdu's reasonable layout of city function, such as city planning, traffic condition, economy and social environment etc. According to the adaptation of Chengdu's fast rail traffic system planning, 7 lines constitute of Chengdu's fast rail traffic system. At present, the 1st and 2nd line of Chengdu metro are already under construction. In the metro construction, first of all, we are faced with the construction of deep foundation pit in the metro station, how we can put the urban deep foundation pit in practice safely, high efficiently, economically is a challenge.The Design and construction of the supporting system in the deep foundation pit are different from the superstructures: the ground water level, the physical mechanics character of the soil and environmental condition etc. are directly related to the selection of supporting system. The deep foundation pit subject is a general subject, which related to engineering geology, soil mechanics, foundation engineering, structural mechanics, techniques in situ test, engineering techniques, the interaction of the soil and structure and environment geotechnical engineering subject etc.At present, the mechanics analysis of the deep foundation pit construction in the big cities in china and have comparative perfect analysis and computing methods, although these methods probably have dissimilarity with the practical situation, but it also has some effect on the guidance of construction and forecast a varieties of under stress condition of deep foundation. And that, for stratum conditions in the Chengdu region, where is lack of the research on design and construction domain of the supporting system in the deep foundation pit, and the theories in this aspect are further continued. In this paper, author had made mechanics analysis on stability aspect of XiaoTianZhu metro station's supporting system in the deep foundation pit, and introduced a software: FLAC^3D(Fast Lagrangian Analysis of Continua in three Dimensions), which is based on explicit method of finite difference, and is popular in geotechnical engineering analysis. Author applied this program on the deep foundation pit construction's numerical simulation, and compared relevant displacement field and stress field combining with practice monitoring and measuring data, proved that in this analysis, the FLAC^3D model and choice of parameter is reasonable. In conclusion, the research on metro station supporting system in the deep foundation pit in Chengdu region still needs more attention, to build up perfect technology regulations of foundation pit supporting system for the Chengdu metro and the construction can be safe, efficiently, economically.