论文部分内容阅读
针对当前大跨度隧道施工中出现的一些问题,选取某城市软土地层中采用双侧壁法施工的大跨度隧道为案例,就导洞初期支护的非均衡设计对地表沉降控制以及支护结构内力转换等方面的影响情况进行分析,分析表明:采用timoshenko分层梁模拟支护以及对支护构件按等效刚度处理是合适的,计算结果与实测规律比较吻合;导洞支护的非均衡支护设计对地表沉降影响较大,内壁刚度过度减弱,将导致中洞开挖阶段的地表沉降值迅速增加,给中洞施工带来压力;非均衡支护设计将直接影响支护结构的最终内力分布及中洞开挖阶段的支护内力转换,而对拆撑阶段支护内力的影响相对较小。
Aiming at some problems in the current long-span tunnel construction, a case study of a long-span tunnel with double-sided wall method in a soft soil formation of a city is taken as an example. In the light of the unbalanced design of the initial support of the guide tunnel, Internal force conversion and other aspects of the situation analysis shows that: timoshenko layered beam simulation support and the equivalent stiffness of the support member treatment is appropriate, the calculated results and the measured law is more consistent; guide hole support imbalance The support design has a great influence on the settlement of the earth’s surface, and the excessive decrease of the rigidity of the inner wall will result in the rapid increase of the surface settlement value during the excavation of the middle tunnel, which will bring pressure to the construction of the middle tunnel. The unbalanced support design will directly affect the final internal force of the support structure Distribution and support during the excavation of the tunnel internal force conversion, while the support phase of the support force is relatively small.