基于体积损失控制法的盾构施工模拟研究

NUMERICAL SIMULATION STUDY OF GROUND SETTLEMENT CAUSED BY SHIELD TUNNELING BASED ON CONTROL METHOD OF VOLUME LOSS

基于体积损失控制法,对北京市地铁8号线沿线典型区段由于隧道施工引起的地层沉降进行模拟。为得到合理的计算结果,以基于地层损失率得到隧道沿线控制断面的地表沉降槽面积作为区段的边界值,对区段内的子区域进行插值,采用不等比例的应力释放方法,通过独立判定各子区域是否完成应力释放以获得隧道沿线连续、渐变的沉降变形。分析隧道开挖影响范围内土体的应力状态变化和位移特性,模拟了隧道沿线的地层沉降,并与Peck算式计算结果和实测数据进行了对比。

Based on control method of volume loss, the ground settlements caused by shield tunneling were simulated,which was located at typical sections along Beijing metro line 8. In order to get a reasonable calculation results,areas of surface subsidence trough of different sections obtained from ground loss rates were taken as boundary values,which were used to calculate those of subareas by interpolation method; the stresses were released according to unequal ratio; the continuous and gradient settlement deformations were gotten by independently judging completion of stress release of subareas. The features of stress state and displacement of soil located within the range of influence of tunneling were analyzed; ground settlements were calculated,whose results were compared with the results of Peck formula and the measured data.