Research Research On Foundation Pit Enclosure Design Of Nanjing Metro Line 7 Control Center

In conclusion,a variety of papers Excavation support scheme based on the characteristics,summarized the advantages and disadvantages of different support schemes and application;analyzes the impact of excavation program selection factors in order to Nanjing rail transit line 7 Excavation cases,elaborated pit BRACING design principles and methods.Nanjing rail transit line 7 pit plane large,roughly rectangular shape(not rules),the strengths of about 227 m,width 88m;field area silt unevenly distributed around foundation distribution pipelines and residential buildings,public facilities,especially the northwest side of a culvert,its excessive settlement and differential settlement is very sensitive.The principle of the foundation pit supporting scheme is selected as follows:first of all,according to different strata,excavation depth,the surrounding environment,according to the importance of foundation pit supporting partitioning,segmented,and then to each paragraph according to from simple to complex,from low to high order are compared,and the trial,both the construction period and other engineering conditions,finally choose the best solution.Through comprehensive comparison decided to support the proposed sites are used as follows: southwest,northwest within the main use of bored piles supporting form of foundation pit supporting,local use double row pile;The southeast area,northeast area mainly uses the bored piles and anchor foundation pit supporting forms.According to the real condition of the soil and engineering around the foundation pit is divided into ten spacing section to carry on the design.Using equivalent beam method to calculate the level of the pile length and anchor rod support;Calculated according to the level of bolt support anchor length,anchor rod design;The stability calculation for the built-in depth;Support design with day han software calculation and drawing construction drawings.