| With the development of engineering construction area in China,more and more slope projects are involved in all kinds of public infrastructure,how to evaluate the slope stability scientifically and how to strengthen the slope safely has become a difficult and hot spot in the engineering construction.Anti-slide pile is the most commonly used supporting structure in slope reinforcement engineering,however,due to different slope projects,different anti-slide piles should be selected according to the actual projects,such as embedded anti-slide pile,cantilever anti-slide pile,composite anti-slide pile,etc,at the same time,it is also necessary to optimize and select the anti-slide pile section,because the round section anti-slide pile can not only use mechanical hole to improve efficiency,reduce safety,but also have a good support effect,so it’s more and more be used widely.In addition,the sliding force borne by the anti-slide pile is different due to the different thrust mode of landslide.In this paper,a new type of variable cross-section anti-slide pile(cantilever section is rectangular or square section,anchorage section is circular section)is used as the supporting structure of similar projects such as the filling slope(subgrade)or cantilever section construction space is limited.As a new type of support structure,this kind of variable cross-section anti-slide pile has different and more complex mechanical characteristics than that of the same cross-section anti slide pile.At present,this kind of research is rare.In this paper,the theoretical analysis,structural model test,numerical simulation and other methods will be used to study the mechanical characteristics and engineering application of this kind of variable cross-section anti-slide pile under different landslide thrust modes.The main research contents and results are as follows:(1)The distribution form and expression of landslide thrust are introduced in detail,and the force calculation formula of new variable cross-section anti-slide pile under rectangle,triangle,trapezoid and other loads is deduced.(2)Through the artificial simulation of rectangular,triangular and trapezoidal loads put on the four kinds of cross sections(square,rectangle,upper square of the lower circle,upper distance of the lower circle)of anti-slide pile were tested on indoor model test.The results show that:There are two peak points on the surface strain curve of variable cross-sectionanti-slide pile,and sudden change emerge at the variable cross-section,while the strain curve of steel bar passing through the anti-slide pile can be regarded as only one peak point,and sudden change also occurs at the variable cross-section,but the strain is basically the same at the-0.15m-0.30 m section of pile body,the stress is uniform,and the strain of constant cross-section anti-slide pile has no sudden change,and its peak strain is larger than the change peak strain of variable cross-section anti-slide pile.(3)Under the same and the same level of load,the displacement of the square section anti slide-pile is the largest,the shape section anti-slide pile is the smallest,and two kinds of variable cross-section anti-slide piles is in the middle(the difference is very small);and the bending moment of the variable section anti-slide pile changes suddenly at the variable section,and its bending moment is smaller than that of the square or rectangular section anti slide pile.(4)When the landslide thrust is equal,the strain of the anti slide pile is: the rectangular load is larger than the trapezoid load and larger than the triangle load,and the earth pressure around the pile and the displacement of the pile also conform to this law.(5)Based on the model test,the conclusion similar to the model test is obtained through numerical analysis,and through the numerical analysis of the actual filling slope engineering,it is confirmed that the variable cross-section anti-slide pile has certain advantages as the support structure. |
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