天津软土地区深基坑开挖对地下管线位移规律的数值模拟研究

Numerical Simulation Research on Spatial Variation of Displacement of Underground Pipeline During Excavation of Deep Foundation Pit in Tianjin Soft Soil Area

以天津市某研发大楼深基坑工程为例,运用有限元模拟方法分析基坑开挖引起邻近管线位移的规律。模拟结果表明,基坑开挖顺序不同将导致管线位移不同,基坑从中间向两边开挖对管线的影响较从两边向中间开挖时要小,且基坑端部为管线曲率改变最大处。对土体的加固可有效减小基坑开挖引起的管线位移,加固土体的深度和宽度不同,对管线位移的限制作用也不相同,结合本工程实际情况,认为加固深度为7 m、宽度为7 m时,是在保证加固效果的前提下最经济的加固范围。

Taking a deep foundation pit engineering of a research building in Tianjin as an example,analysis adjacent pipeline displacement rule caused by foundation pit excavation with the finite element simulation.Simulation results show that different excavation sequence will lead to different displacements of pipeline,the influence on pipeline from middle to both sides excavation is smaller than that from both sides to the middle excavation,and at the end of the foundation pit is the maximize curvature change of the pipeline.The soil reinforcement can effectively reduce the displacement of pipeline caused by foundation pit excavation.Different depth and width of reinforced soil will result in different restrictions on pipeline displacement function.In combination with the practical situation of the project,believe that when the strengthening depth is 7 m and the width is 7 m is the most economic under the premise of best reinforcement effect.