地铁暗挖通道施工对既有桥桩的变形特性分析及施工处理措施

Analysis of Bridge Piles Deformation and Construction Measures of Subway Underground Excavation

以沈阳地铁4号线观泉路站为背景,对暗挖隧道施工中的一级风险源——隧道侧穿高架桥的施工过程进行了仿真数值模拟。按照国家相关规范标准,桥桩间的差异沉降不得大于5 mm,这对暗挖侧穿段的施工提出了较高要求。数值模拟计算结果表明,暗挖隧道侧穿桥墩,桥面沉降呈现双沉降槽形式,沉降槽位于桥墩内侧1/6跨度处,沉降反弯点位于桥墩1/6跨度处。通过对侧穿段的土体进行注浆加固,可以有效控制暗挖隧道施工引起的桥桩沉降及不均匀沉降,从而保证既有高架桥的运营。

By taking Guanquan Road station of Shenyang subway line 4 as an example, this paper carried out the simulation numerical simulation of the primary risk source of underground tunnel construction-tunnel across viaduct from the side. According to the relevant national standards, differential settlement between bridge pier should not be greater than 5 mm, which put forward higher requirements to underground side wear period of constmction. Numerical simulation results show that, when tunnel across viaduct from the side, bridge deck subsidence takes the form of double settling tank. Settling tank is located in the medial 1/6 span bridge piers and settlement of inflection point is located at pier 1/6 span. Through the side wear period of soil grouting reinforcement, we can effectively control the underground tunnel construction of bridge pier settlement and uneven settlement and ensure the operation of the constructed viaduct.