顶管施工三维数值模拟及土质适用性研究

3D Numerical Simulation of Pipe Jacking and Its Soil Applicability Study

为了研究大直径顶管在不同土质中施工的适用性,结合广州市某引水工程,对外径2.8m、壁厚0.028m的顶管隧道施工进行了三维数值模拟。通过模拟结果与Peck经验公式对比,验证了所建模型能够反应顶管施工造成地层扰动的基本规律,并得出地表沉降横向和纵向的受影响范围分别为-3.6～3.6D和-2.14～2.14D(D为外径)。基于以上模型,改变顶管穿越土层的土性参数,得出了不同砂性土的模量及摩擦角、粘性土的模量及粘聚力、顶管穿越复杂土层情况下地表沉降的变形规律,并对顶管隧道不同土质条件下的适用性进行了初步讨论。

Based on a water diversion project in Guangzhou,a three dimensional numerical modeling was performed on pipe jacking tunnel with external diameter of 2.8m and thickness of 0.028m for studying soil applicability when the big pipe jacked in soils of different nature.Compared with the empirical formula Peck,the model could reflect the basic law of ground disturbance caused by pipe jacking,and reduced the transverse and vertical incidence of surface settlement which is-3.6~3.6D and-2.14~2.14D.Based on the above model with changing parameters of soils which the pipe jacked in,the law of surface is studied subsidence in the case of different modulus and friction angle of sand soil,different modulus and cohesion of cohesive soil,and complex layers which the pipe jacked in,and the applicability of soils of different nature which the pipe jacked in is discussed.