Abstract:In view of the multiple rows of parallel pipe jacking construction disturbance problem and the deficiency of existing model test equipment, an indoor pipe-jacking model test system was developed to precisely control the grouting pressure of pipe wall, the pressure of soil bin and the soil loss rate. Based on the reconstruction and expansion of water supply and drainage pipe network in Haikou city, the effect of near distance pipe jacking on the vertical deformation of existing pipes and the ground surface is studied by means of pipeline embedding. The results of this test verified that the developed indoor model test system can accurately control the grouting pressure of pipe wall, the pressure of soil bin and the soil loss rate. The data obtained by the test system are correct and reliable; In order to select proper grouting pressure in actual site, it is necessary to realize vertical surface deformation control, that is, to coordinate with the cutting rate and jacking rate of the machine head, and to strictly control the excavation rate to balance the soil bin pressure and formation pressure. Pipe jacking produces additional stress on existing pipelines, but the additional stress is far less than the surrounding rock stress, so it is unnecessary to consider the effect of additional stress on the bearing capacity of pipe segments in the actual site. In the model test, the grouting pressure is reasonable, but the cutting rate of the machine head is not enough to guarantee, and the excavation rate is slow, which leads to the surface uplift all the time,these two parameters need to be further adjusted in subsequent tests.