单舱双线顶管穿越对构筑物及隔离桩影响分析

Analysis of the influence of single-cabin double-line pipe jacking on structures and isolation piles

依托西安市330kV综合管廊架空线落地改迁项目,将Peck公式沉降曲线、有限元模拟与工程实测结果进行对比分析。运用有限元分析的方法,在ABAQUS中模拟为避让即临构筑物而采取单舱双线大口径管道顶进的过程,分别采取三个工况下的隔离桩变形数据,同时提取构筑物的变形数据并与工程实测进行对比,得到随着顶进距离的增加隔离桩的变形规律及保护构筑物效果。结果表明:通过模拟方法的对比分析,可以证明采用ABAQUS有限元模拟的施工过程与实际结果较为接近。当采用单舱双线施工时,两管线之间的隔离桩均发生一定程度的变形,形状类似于抛物线,即中间靠近管道的位置产生靠近构筑物的凸起变形,顶进距离较h变形值不明显,当顶进在10m左右时承台及隔离桩形变变化率最大,其中隔离桩变形最大值为2.5mm。随着顶进距离的增加变形逐渐增大,但桥墩承台变形值过小且不成规律性,在顶进过程中承台变形最大值在0.1mm左右,可以证明隔离桩有效地减小了顶管施工对承台的影响。

Based on the 330kV ground relocation project of overhead v comprehensive pipe gallery in Xi’an, the settlement curve of Peck formula and finite element simulation were compared with the measured results.Using finite element analysis method, the simulation of single-diameter pipe jacking in ABAQUS, three isolation pile deformation data, extract the deformation data of the structure and compare with the engineering measurement, obtain the deformation rules and the protective structure effect with the jacking distance.The results show that the comparative analysis of the simulation method shows that the ABAQUS finite element simulation is close to the actual results.When using single cabin double line construction, the isolation piles between the two pipelines deformation to a certain extent, shape similar to the parabola, that is, the middle near the pipeline produces the convex deformation near the structure, the hourly deformation value of the jacking distance is not obvious, when the jacking is about 10m, the bearing and isolation pile deformation rate, the maximum deformation value of the isolation piles is 2.5mm.With the increase of the jacking distance, the deformation value of the pier abutment is too small and irregular. During the jacking process, the maximum deformation value of the abutment is about 0.1mm, which can be proved that the isolation pile effectively reduces the impact of the jacking construction on the abutment.