浆液扩散是影响顶管注浆减阻的关键因素,为此建立顶管三维数值分析模型,引入扩散环模拟顶管施工过程中浆液的扩散过程,根据管周土体与管片接触情况修改管土摩擦因数,研究顶管施工过程中浆液扩散过程对减阻效果的影响.将计算得到的顶进摩阻力与实测数据进行对比,验证方法的可靠性,进一步研究了顶管施工过程中滤过效应对土体位移的影响及注浆扩散相关参数对顶管施工过程中土体位移及顶进摩阻力的影响.结果表明:考虑滤过效应时的地表沉降更小;滤过效应引起的渗透系数衰减越强则地表沉降及顶进摩阻力越小;浆液扩散的越快,泥浆套越完整,则顶管顶进期间的注浆减阻效果越好.

Slurry diffusion is the key factor affecting the resistance reduction of pipe jacking grouting. Therefore, this paper establishes a three-dimensional numerical analysis model of pipe jacking, introduces a diffusion ring to simulate the slurry diffusion process during pipe jacking construction, modifies the friction coefficient according to the contact between the soil around the pipe and the segment, and studies the influence of the slurry diffusion process on the resistance reduction effect during pipe jacking construction. The calculated jacking friction is compared with the measured data to verify the reliability of the method proposed. The influence of the filtering effect on soil displacement and the influence of grouting diffusion-related parameters on soil displacement and jacking friction during pipe jacking construction are further studied. The results show that the surface subsidence is smaller when the filtration effect is considered; The stronger the attenuation of permeability coefficient caused by the filtration effect, the smaller the surface settlement and jacking friction resistance; The faster the slurry diffuses and the more complete the slurry jacket is, the better the resistance reduction effect of grouting during pipe jacking.