Study On The Stability Of Rock Slope Of Tunnel Entrance Under Dynamic Load

The dynamic load caused by tunnel rock slope slip is a common geological disasters inthe field of Engineering. With the rapid development of our national economy, a lot ofhighways and other infrastructure construction, it will inevitably encounter the slope problems.Its stability is extremely easy to be influenced by the construction of Engineering. Hence, Ithas important significance to investigate the stability of tunnel portal slope. This paper rely onthe part of the expressway of Xi’an-Shangzhou in Shaanxi province. Using finite elementanalysis software MidasGTS, the stability of tunnel rock slope numerical analysis has beendone. Research contents are as follows:(1) The original terrain contour based on the numerical analysis model are established.Compared to the model than the traditional method of model, it can be a true reflection of theoriginal slope landform characteristics.(2) The tunnel entrance slope in the construction disturbance and dynamic load of twokinds of conditions for numerical simulation. The analysis considers the effect of changes inthe structure and surface parameters on slope stability By searching the most dangeroussliding surface, the maximum displacement, maximum stress and other key indicators,analysis of the influence of layer thickness, the shear strength parameters of rock mass, thedensity of the index parameter. The results show that: rock slope of tunnel entrance is underdynamic loading can increase the sliding moment, the slope is Prone to slip. The mostdangerous slip surface is in slope range.(3) It select two typical tunnel rock slope, To using the new measured contour line, thetrue model of the rock slope was created. In the natural state and dynamic load (blasting load)in two cases, the slope stability analysis was done. Instability will aggravate the slope, whenthe rock slope under dynamic load, entrance slope displacement increases. Compared with thestate of nature, the failure occurred at the foot of the slope range, The proposed constructionduring the period of the slope angle near the level of reinforcement.