Study On Environmental Protection Of Metro Shield Construction In Tianjin

With the development of Tianjin’s metro and light rail construction, shieldtunneling technology was used. During of shield construction, land subsidence controltechnology become more and more mature, but groud settlement control technologyof shield tunnel is not yet mature for the engineering characteristics of geologicalconditions of the Tianjin area.This paper research on land subsidence control andenvironmental protection technology of the western part of ZHONGSHAN GateShield of rapid rail transit project in TIANJIN BINHAI New Area, through theseresearch summed up a set of land subsidence control and environmental protectiontechnology in TIANJIN area, shield tunnel construction in TIANJIN has a veryimportant technical guidance and reference will be larger technological, economic andsocial benefits.In this thesis, a variety of methods have been applied to process the datacollected on land subsidence during the construction of rapid rail transit line fromurban area to Binhai new section in Tianjin. Additionally, a Peck model was selectedto forecast the settlement.After contrasting the forecast to actual data on landsubsidence, and amend the parameters range of the mathematical model. A law ofshield tunneling construction causing land subsidence has been found and used as aforecasting tool so as to minimize and avoid the environmental impact caused by theland subsidence during subway shield tunneling construction.Research results:(1) Establishing the main content and the specific method ofshield tunnel construction monitoring in TIANJIN region.(2)This paper ascertaining the parameters range of index curve function ofvertical subsidence(A-15～-20mm，B0.03～0.09，S0-3mm～7mm,x00～5m). Takeurban rapid transit engineering of TIANJIN BINHAI new area for example to processresearch, revising two important parameters of peck formula in transverse subsidencerule (V to1.0%to1.5%from0.5%to2.0%, k0.4-0.6to0.5-0.6).(3)According to the actual working conditions of project in TIANJIN area,specific and feasible monitoring program and control standards were put forward.(4) Feasible the construction technical measures were put forward when shieldtunnel through special building (structure) building (dangerous buildings) and underground pipelines.(5) Proposed and summary of the environmental protection programs in thesphere of influence of the shield construction.