大型地铁十字换乘车站施工阶段变形预测

DEFORMATION PREDICTION DURING CONSTRUCTION OF CROSS INTERCHANGE TRANSIT STATION

枢纽车站大多位于城市中心,具有埋深大、结构复杂、变形要求严格、施工组织与施工技术困难等特点。以上海轨道交通8号线与10号线大连路换乘车站为工程背景,应用深基坑设计理论和有限元方法,对预留换乘枢纽车站施工过程中的关键工况,进行内力和变形计算。计算结果表明,换乘枢纽车站的非对称挖土和非对称凿除地连墙留洞是换乘枢纽车站施工中最危险工况,提出在施工中加强地下连续墙、地面变形的监测,尤其在非对称凿除地连墙时,加强对换乘段梁、板、柱内力变形监测;同时采取坑底土体加固、增设临时支撑等一些施工技术措施的建议,以确保车站安全施工。

With the development of urban railroad transit network in China,the complex construction of interchange station will be a new technical problem for building the whole railroad transit network. In order to provide technical support for safe construction of Dalian road interchange station in Line 8 and Line10 in Shanghai,numerical analysis is used to simulate the whole construction process. With designing theories of deep foundation,the finite element method and ANSYS software,the deformations in main construction cases are calculated. According to the analysis,the conclusions can be drawn as follows:the asymmetric excavation and the asymmetrically chiselling-off of the diaphragm wall are the most dangerous constructions cases;the deformation of the diaphragm wall and ground should be measured during the whole construction,especially,the internal forces of the beam,plane and column in interchange connection should be measured when the diaphragm wall was asymmetric chiselled off. Some reinforcement methods such as ground reinforcement,temporary support should be used if necessary.