Research On The Stress Distribution Law Of The Micropile Reinforcing Landslide In Shallow Accumulation Layer

In China various types of geological hazards, landslides proportion as high as 50%. Shaanxi landslide territory in a variety of geological disasters is to reach 62.3% of GDP, while the shallow debris landslide reached 65% in all types of landslide, which carried out for the shallow accumulation layer of reinforcement to prevent landslides technology has a major the practical significance. With the development of landslide disaster prevention technology micro piles Due trenchless construction of landslide disturbances small pile flexible layout, construction speed and good economic and other characteristics, this year accumulation layer in shallow landslide more and more applications. But micro-pile reinforcement landslide theoretical research lags far behind the application of engineering practice.Aiming at this situation, a similar principle as the theoretical basis for the framework of the model test as research tools, micro pile reinforcement stress distribution of shallow slope during pile accumulation layer were studied. Under the test by a single row of piles, double pile, plum-shaped layout of the three rows of miniature pile reinforcement shallow debris landslide experiment, explore reasonable pile spacing, row spacing, and even micro-pile top tie beam conditions laid mini distribution of anti-slide pile in the pile during stress. Through five groups of experimental data analysis model test, the main conclusions are as follows:(1) When not laid micro pile, top of the hill after loading 5.6kpa, landslide instability and failure to reach a critical stage, and a reasonable pile arrangement of three rows of piles trials landslide reached the stage before sliding FAILURE, top of the hill needs to be applied 24.7kpa, which can be seen Micropiling improvement in the level of landslide stability is very obvious, micro piles accumulation layer applied to shallow landslide reinforced control project is feasible.(2) Working under different test conditions, and ultimately destroy the form of micro-piles showed consistency, ie near the surface slippery, slippery surface above the pile by the Dutch section of the front edge of the sliding body bending, sliding surface at anchoring segment to slide bed trailing edge bending, bending under the pile slippery surface tilt deformation occurs between points, the rest of the pile no deformation occurs, remain upright.(3) Shallow accumulation layer landslide governance, reasonable pile spacing desirable 8-12d, reasonable row pile spacing can be selected within the range 10d, while the top of the pile even tie beam laid on top of the pile displacement limit can play a significant role. Plum-shaped layout of the pile group tests, even the tie beam laid pile partition pile displacement ratio is not even tie beam partition layout pile displacement decreased 25.6%, while the pile of stress in the pile of plump and more uniform stress distribution only concentrated in the vicinity of the non-slip surface.(4) By comparing the rapidly growing pile of displacement, stress increases rapidly pile, pile soil arching between piles pressure damage begins to decrease loading time and the corresponding crest vertical uniform load, we can see the development of these three test events basic occur simultaneously, thus strengthening the stability situation after the landslide, on top of the pile by horizontal displacement monitoring to achieve.