双洞单线盾构隧道穿湖施工引起的地层沉降分析

Analysis on stratum settlement induced by construction for double-tube single-track shield tunnels passing under the lake

双洞单线盾构隧道之间的相互作用会使隧道上方土层的沉降分布与单洞单线情况不同,而隧道上方地表湖水的存在会改变隧道上方土体有效应力的分布及大小,这也将影响双洞单线盾构隧道上覆土层沉降的大小。基于Verruijt和Booker的解析解并结合等效刚度原理,推导了双洞单线盾构隧道穿湖施工引起的地层沉降计算公式。结合北京地铁14号线枣营站至东风北桥站工程,运用相应的公式对地层沉降进行计算分析,与现场监测结果对比显示吻合较好,验证了本公式的合理性和适用性。

The settlement distribution of double-tube single-track shield tunnels is different from that of single-tube single track shield tunnel because of the interactions between the double tube tunnels. Meanwhile,the distribution and magnitude of effective stress in stratum are changed when the double-tube single-track shield tunnels passing under a lake,which can also lead different settlements to the overlaying soil of tunnels. Based on the stiffness equivalent method and the analytical solution proposed by Verrujit and Booker,a new calculation equation is derived to calculate the stratum settlements when double-tube single-track shield tunnels passing under a lake. Combined with the project of section between ZAO YING station and DONG FENG BEI QIAO station of Beijing Metro Line 14,layered the settlements are calculated using the new equation. It shows that the analytical results agree with the site monitoring results. This proves the rationality and applicability of the proposed equation.