Study On Ground Deformation Law And Control Of Shallow Pipe Jacking Crossing Lane

Trenchless pipe jacking construction can avoid the excavation of the ground,at the same time,it is prone to land subsidence,uplift and other diseases,affecting the comfort and safety of vehicle traffic.In view of this problem,relying on specific projects,combined with field investigation and sampling,consulting specifications,numerical simulation and on-site monitoring,the influence mechanism,development process and settlement influence of various factors on soil deformation and pavement settlement are studied from the aspects of jacking force,grouting pressure,friction resistance and construction stage According to the specific construction process,the corresponding suggestions are put forward to optimize the construction process,so as to effectively control the pavement settlement in the process of pipe jacking.The research results show that:(1)when the working face of the pipe jacking machine passes through the monitoring plane,the motorway heaves.After the pipe jacking machine passes through,the ground begins to settle from the pipe jacking axis to both sides.With the construction progress,the scope and degree of settlement gradually expand until it is finally stable;(2)post construction grouting can reinforce the soil that causes structural damage In a certain range,its effect is positively correlated with the grouting pressure;(3)the reduction of friction between the pipe jacking machine and the surrounding soil has little effect on the control of ground settlement,which can be ignored;(4)according to the numerical simulation results,the settlement of the road surface can be effectively controlled The descending effect is in the order of grouting pressure,jacking force and friction.When the grouting pressure of 120% equivalent stress of working plane + 100%Face thrust at 100% equivalent stress of working plane,the settlement of motorway is the smallest.