Study On Landslide Treatment And Anti-slide Pile Arrangement In The Section Of Aimin Tunnel

In this paper,based on the landslide control project beside Mudanjiang Aimin tunnel entrance section,carried out the following aspects of the study:Firstly,the CX-901 F incline--meter was used to measure the depth of the landslide,and the deviation,mileage and elevation of the surface were measured by the total station to infer the depth of the sliding surface and the volume of the sliding body.Secondly,the anti-slide piles are used to calculate the layout position,section size,anchorage depth and pile spacing of the anti-slide piles on the slopes.Thirdly,to optimize the calculation design of the wall thickness of the rectangular excavated pile.Fourthly,describe and practically applicate the combination of finite difference method software FLAC3 D and landslide treatment and the theory of strength reduction based on equal coefficient reduction of rock and soil cohesion and internal friction angle.The conclusions are as follows.1.The results of the landslide test in the entrance section of the Mudanjiang Aimin tunnel are as follows.The landslide position is within 8.5m from the surface.And then according to the Aimin tunnel geological profile can be observed that the slide surface is actually a layer of gravel soil layer 1-1.5m thick deeped between silty clay and sandstone layer.After a continuous measurement of seven oblique holes for two months,the volume of Landslide was roughly estimated to be about 1.01 x 104 cubic meters,the surface area is about 202 square meters,so it belongs to a small landslide,and the main slip profile is determined.2.According to the transfer coefficient method,the remaining slip force of the main slip surface of the landslide of the Mudanjiang Aimin tunnel is calculated as P = 75.96 × 10 3KN /m2.The line distribution pressure acting on the anti-slide pile above the slip surface is q = 12.06 KN / m.According to the force of the pile and the site conditions,determining the anti-slide pile cross-section size as 2.0m × 2.5m,the anchorage depth of the pile is 3.2m,the distance between the pile and the pile is 6.0m.And set a linear single row of piles,to the direction vertically to thr slope.3.According to the "soil arch principle" and Langham earth pressure calculation method,the maximum earth pressure value is reached when the digging pile is 5.4 m away from the surface,Through the maximum bending moment formula derivation and calculation determine that the rectangular artificial digging pile wall thickness as 20 cm.4.The strength reduction method based on FLAC3 D is to adjust the strength index c and ? of rock and soil by increasing the reduction coefficient continuously until it reaches critical damage to quantify the stability coefficient of slope.In this paper,the landslide stability is analyzed under the four conditions of natural conditions,slope foot excavation,slope foot backfill and after the treatment.The results show that the landslide displacement and the shaping area are controlled,the stability is improved greatly and the control effect is good after setting the anti-slide piles.