Research On Stability Of Liushigou Landslide And Soil Arching Effect Of Anti-slide Pile

Lingtai-Huating Expressway is an important part of the northwest high-speed network.The slip-slip landslide studied in this paper is located in the corridor where the line is laid,which seriously restricts the smooth construction of the proposed highway.In order to stabilize the construction of the expressway,in the case of familiarity with the regional geology,the field survey was carried out.In order to find out the geological engineering characteristics and evolution process of the landslide,various methods including in-situ test and indoor test were used.Means;For the stability of landslide,the limit equilibrium method was used for quantitative evaluation.The MIDAS/GTS finite element analysis software was used to establish the pseudo three-dimensional numerical model to check the stability of typical sections under different working conditions,and analyze the stress and strain.The characteristics of the displacement change,and at the same time simulate the anti-sliding effect of the anti-slide pile after treatment.The influencing factors of anti-slide pile layout were changed,and the soil arching effect under different pile spacing,internal friction angle and landslide thrust was discussed.The main results of this paper are as follows:(1)The basic morphology,material composition and structural characteristics of the landslide were ascertained through field exploration,drilling,laboratory tests and other geological means.The evolution process of the landslide was analyzed,and the main factors leading to the revival of the landslide were the geotechnical structure and rainfall.,earthquakes and human engineering activities.(2)Using the transfer coefficient method to analyze the stability of landslide under different working conditions: including natural working conditions,heavy rain or continuous rainfall conditions,heavy rain and seismic conditions.The results show that: 1 is stable under natural conditions,2 rainstorm or continuous rainfall conditions are basically stable ~ steady state,3 storms and earthquake conditions are basically stable ~ unstable state.(3)Establish a three-dimensional numerical model of the II-II’ section of the landslide in the MIDAS/GTS analysis software,and analyze it: under natural conditions,the stress issmall and large,and the shear strain is concentrated at the sliding zone.The through-slip surface is formed.Under the condition of saturated water and earthquake-saturated water,the stress,shear strain and total displacement trend of the landslide are similar,the degree is larger than the natural state,and the stability of the landslide is also worse.Stability calculation and software simulation The stability factor results are similar.(4)Using MIDAS/GTS analysis software to simulate the landslide after treatment,the shear stress area is obviously reduced before and after the treatment,and the shear strain is greatly reduced.It can be seen that the total displacement of the landslide is significantly less than that before treatment.The amount of displacement has obvious effects.The post-governance stability factor calculated in the MIDAS/GTS software meets the specifications.(5)Change the layout conditions of anti-slide piles in MIDAS/GTS analysis software,and analyze the influence of different pile spacing and internal friction angle on soil arching effect: in the process of increasing the spacing of anti-slide piles,the soil arching effect first The reinforcement is weakened.After a certain distance,the soil arching effect no longer works.During the process of the internal friction angle from 0° to 15°,the soil arching effect increases obviously,and the internal friction angle increases from 15 ° to 30 °.During the process of,the soil arching effect continues to play a role,and the growth rate is slow.During the process of increasing the cohesion from 0kpa to 15 kpa,the soil arching effect is enhanced,which is beneficial to improve the anti-slip effect of the pile.During the process of increasing the internal friction angle from 15 pka to 30 kpa,the soil arching effect continues to function but is no longer enhanced.