Research On Mechanism And Compacting Effect Of High Pressure Jet Grouting Pile

The high-pressure jet grouting method is a stratum reinforcement technique which isdeveloped in rencent years. For its characteristics, which are high strength for the reinforcedmaterial, controllable reinforce range, strong adaptability to the stratum and also have a goodeffect in dealing with soft soil, dirt, aqueous soil. So it is widely applied in the foundationtreatment, waterproofing,water-stop, tunnel lining in recent years. However,its design methodis still based on the comparison of engineering experience, the optimizing of design parameteris lack of theory basis, the research on its mechanism of pile soil and compacting effect is farfrom enough.Firstly this paper is based on its mechanism of high-pressurejet grouting pile, using theidiscrete element method (DEM) analysis method, overcomed traditional continuummechanics model of the assumption of the continuity, to study the movement of soilparticles,the stress transfer characteristics of micro-structural changes,the law of jet’sdiffusion and stress decay. And then in using the finite element method (FEM) numericalanalysis method, discussed the compacting effect in the process of jet grouting.At last,basedon the engineering example, we can analysis the influence of using high-pressure jet groutingmethod in different range on different soil and former structures, it can provide theory basisfor design and rational suggestions.The study shows that:a)in the process of jet grouting,it can lead to soil compaction,suchas clay, it is easy to appear splitting failure,but its stress decay is faster than sand,and for softsoil,it will happen splitting failure in a short time with wide splitting range and slow stressdecay;b) A higher injection pressure or a longer duration can lead to a higher excess porewater pressure and lateral displacement of soil;c) using reasonable construction sequence canreduce the adverse effects during the jet grouting pile construction, such as the symmetryconstruction, the construction process by nearly to the far, and keep3meters above distancewith buildings.