Research And Engineering Application Of Anti-slide Pile Soil Arch Effect

With the advancement of the infrastructure construction in mountainous areas,the number of(sliding)slope projects that need to be reinforced is gradually increasing.As an efficient anti-sliding support structure,anti-sliding piles have been widely used in slope reinforcement and other projects.At present,the academic and engineering circles at home and abroad have reached a consensus on the anti-sliding mechanism of anti-sliding piles.It is believed that anti-sliding piles exert their anti-sliding effect through the joint action between piles and soil.The interaction mechanism between piles and soil is soil arch effect,and the strength of soil arch effect is the key to give play to the anti-sliding effect of piles.Therefore,it is necessary to reasonably design the anti-sliding piles to ensure the maximum effect of soil arch effect between piles.Based on the guzhang county of Hunan province of geological disaster prevention projects as the background,the soil arch effect of the three factors that affect the pile spacing,pile width and embedded depth were studied,and the quadratic orthogonal regression test as the research method,using FLAC3 D model test index,and then based on the experiment of detected data for the design and calculation of working conditions,the main research contents and results are as follows:(1)Obtained through numerical simulation test pile spacing,pile width and embedded depth three influence factors and soil arching effect,the regression equation between the respective optimal solution can be got as follows:the pile spacing of 8.98 m,2.33 m wide,buried depth of 9.37 m.Considering the engineering safety reserve,and the ultimate bearing capacity of foundation requirements,appropriate reduction for the optimal solution of the above request,working condition of the resulting four groups:Working condition 1: pile spacing is 6.0m,pile width is 2.3m,and buried depth is 11mWorking condition 2: pile spacing is 6.3m,pile width is 2.3m,and buried depth is 11mWorking condition 3: pile spacing is 6.6m,pile width is 2.3m,and buried depth is 11mWorking condition 4: pile spacing is 6.9m,pile width is 2.3m,and buried depth is 11m(2)By analyzing the modeling of different working conditions,the development rule of soil arch effect in the load-bearing segment under the same working condition is first strong and then weak,the bottom position is stronger than the top position of pile,and the strongest position is the lower part of the load-bearing segment located at 4m from the top of pile.Same parts(from the pile top 4 m)under different working conditions,working condition of a condition,conditions and three soil arching effect is strengthening,and the growth rate is larger,working condition between the working condition of three to four still increase,but growth is abate,the soil arch effect in the condition of maximum around,considering the working condition of the soil arch effect three also got good play,therefore Screen workingcondition 3 and 4 for the next design calculation.(3)According to the calculation,the amount of reinforcing steel of single anti-sliding piles in the working condition 3 is about 5.693 t,the total amount of anti-sliding piles is 15,the total amount of steel used is 85.40 t,the amount of reinforcing steel used for single piles in the working condition 4 is 6.028 t,the total amount of anti-sliding piles in the working condition is 14,and the total amount of steel used is 84.392 t.The innovation of this paper lies in the use of quadratic orthogonal regression test to simulate the experiment,which not only studies the effect of a single factor on the soil arch effect,but also analyzes the coupling effect between the two factors.In addition,according to the regression equation obtained by quadratic orthogonal regression test,the local optimal solution of three unknown quantities can be obtained,so that multiple working conditions can be formed,and different working conditions can be studied and analyzed.