The Mechanism Of Micropile Reinforce Shallow Expansive Soil Landslide

When designing a variety of geological disaster, for ensuring social stability and development, traditional retaining measures have not satisfied the management needs. With the requirements increasing, the management works for landslide are moving forward into light weight and small type. Grouting miniature supporting system emerges as the times require. Comparing the traditional retaining construction, micropile is characterized with fast construction, small perturbance, well effect and wide applicability. Then as a new technology to manage the landslide and side slope, micropile appears later. In practical projects, it prefers the experiential theory rather than the incomplete calculation theory. The landslide reinforcement theory of micropile is at an early stage, while it is disadvantageous to develop the micropile in the future.Based on the analysis of the testing research results of the worldwide scholars, this paper used the numerical simulation method-FLAC3D to simulate the variation of stresses and strains of the slope when the mini-piles reinforced the expansive soil landslide. The variation law of the mini-pile's working performance caused by different affecting factors was analyzed. The meaningful results provided materials for the future research of mini-pile.The effect of mini-piles reinforcing landslide was obvious. Compared with the traditional retaing structure, the mini-pile belonged to flexible supporting. The mini-pile resisted the down force through its own stiffness. The mechanical properties of soils around the pile were improved by grouting. The mini-pile were know as a supporting system. Under the condition of reasonable design parameters, more than 90% of the displacement of the sliding surface was decreased by the mini-pile. The plastic zone of the slip mass disappeared. The single pile can produce its own sliding action in the range from 8D to 10D. Take the first row of the mini-pile for example, the variation of strains of the piles increases with the row spacing from 10D to 13D. The embedded depth of the pile is the best from 1/3 to 1/2.The research results of the mini-piles provide a better theoretical material, and have a positive significance on the shallow treatment of expansive soil landslide and design of mini-pile construction.