The Indoor Columnar Model Experiment On The Flexibility Drainage Pine Poles Reinforcement Soft Soil Foundation

With the development of the 13 th Five-Year Plan and the construction of ecological civilization,the soft foundation treatment technology economic and the ecological problems facing the increasingly significant.Combining drainage consolidation theory in engineering,and pine piles in the treatment of the upper light-load such as small and medium-sized roads and water conservancy engineering have good performance in the soft soil foundation,group design a new drainage pine piles,the drainage geotextile with traditional organic coupling pine piles processing soft soil foundation.As the main bearing can also take note of the effect of drainage consolidation,conform to reduce the consumption of non-renewable resources concept such as sand and gravel,improve economic efficiency.The article based on our group prophase research of the indoor drainage pine piles strengthening soft soil foundation of pine piles did not penetrate soil test,single pile drainage effect influence factors,through the design of indoor model test simulation scheme under different external load of single drainage pine wood processing cylindrical soil consolidation process.mainly including the following aspects :(1)On the basis of indoor consolidation test model to design test model,according to the theory of sand drain drainage effective radius to design test model sample soil basic mechanical parameters.(2)Proceed the basic physical and mechanical parameters of soil test experiment,focuses on the consolidation parameters;(3)Using indoor model device comparison research different drainage conditions.Research various drainage conditions(Pure vertical drainage,only put pine pole,put drainage pine pole,put drainage pine pole pure radial drainage and put drainage pine pole two stage equal load to 200 kpa),different pine pole diameter(8 mm,10 mm,12 mm),different drainage structure layer(one layer and two layer,four layers of geotextile,hollowtwo layers of geotextile and geotextile roll bar)processing cylindrical specimens of drainage consolidation effect.(4)Discuss columnar samples with the test data by all sorts of conditions for reinforcement pattern on its consolidation rate and reinforcement effect,by analysis mechanical parameters of soil test after reinforcement before and after and undrained shear strength,study the effect of various factors and their change rule.(5)According to the measured data by using improved Takagi Shunsuke method and exponential curve method to calculates final settlement,the inversion of the process of consolidation coefficient β and the average degree of consolidation time U,for drainage of pine wood design experiment basis for applied to engineering practice.Model test research results are as follows: Under the same consolidation pressure and time,drainage pine wood processing the cumulative settlement of soft clay column is larger than pure vertical cylindrical soil drainage consolidation,and its drainage effect is mainly caused by the drainage of medium of pine poles body package;Different diameter of pine poles package the same layer of drainage geotechnical cloth,drainage effect with the increase of poles diameter increasing trend;Due to the effect of jogged of the geotechnical cloth each other,with the increase of geotechnical cloth layer,its drainage increment is geotechnical cloth area utilization rate of yield reduction;And pure geotechnical cloth reinforcement effect is inferior to drainage pine poles,it is concluded that the pine poles support can provide pore water dispersal with continuous fixed drainage channels;Test sample been mechanics performance test show that the parcel after drainage pine wood pole of geotextile reinforcement soil shear strength and bearing capacity is greatly improved.