地下水渗流作用下的盾构隧道开挖面安全系数上限分析

发布时间：2018-07-03 19:57

本文选题：地下水渗流 + 上限分析　；参考：《岩土工程学报》2017年08期

【摘要】：利用数值模拟技术对地下水渗流情况下盾构隧道开挖面的渗流场进行模拟,获得了隧道开挖面周边各节点的孔隙水压力。基于极限分析上限定理,利用各节点孔隙水压力计算出隧道开挖面上限破坏机制中的孔隙水压力功率,并将其视为一个外力功率代入虚功率方程中,构建出考虑渗流影响的开挖面安全系数目标函数。通过非线性序列二次规划法对该目标函数进行优化计算,得到开挖面安全系数上限解。利用强度折减法验证了该方法的有效性,并将其用于考虑地下水渗流作用的盾构隧道工程实例分析。研究表明:在考虑地下水渗流的情况下,开挖面安全系数随土体黏聚力、摩擦角、开挖面支护力的增大而增大,随地下水位的升高而减小;开挖面的破坏范围随摩擦角的增大而显著减小,但地下水位线的位置对开挖面的破坏范围影响较小。
[Abstract]:The seepage field of excavated surface of shield tunnel under the condition of groundwater seepage is simulated by numerical simulation technique, and the pore water pressure of each node around the tunnel excavation surface is obtained. Based on the upper limit theorem of limit analysis, the pore water pressure power in the upper limit failure mechanism of tunnel excavation surface is calculated by using the pore water pressure of each node, and the pore water pressure power is regarded as an external force power to be substituted into the virtual power equation. The objective function of safety factor of excavated surface considering seepage effect is constructed. The optimization of the objective function is carried out by the nonlinear sequential quadratic programming method, and the upper limit solution of the safety factor of the excavated surface is obtained. The effectiveness of the method is verified by using the strength reduction method, and it is applied to the analysis of shield tunnel engineering with groundwater seepage. The results show that the safety factor of excavated face increases with the increase of soil cohesion, friction angle, excavation support force, and decreases with the increase of groundwater level. The damage range of the excavated surface decreases significantly with the increase of the friction angle, but the position of the underground water level has little effect on the damage range of the excavated surface.
【作者单位】：长沙理工大学土木工程学院;约瑟夫傅里叶大学法国国家科学研究院3SR实验室;
【基金】：国家自然科学基金项目(51308072,51678071) 湖南省教育厅科研项目(15C0052) 长沙理工大学土木工程优势特色重点学科创新性项目(15ZDXK13) 国家留学基金项目(国家建设高水平大学公派研究生项目)
【分类号】：U455.43

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