Study Of Stability And Disaster Control Of Consequent Bedding Rock Slope On Ramp A Of Tangtun Expressway

With the rapid development of infrastructure construction, the problem of the stability in consequent rock slope is met frequently in highway construction. The past engineering practice shows that the consequent rock slope is most likely to failure in the rock slopes,and it causes enormous loss of the engineering project and the life and belongs of the people. So,how to analyze the stability of the consequent rock slope and raise the reasonable design scheme to prevent the failure of the consequent rock slope and control the deformation of the slope become difficult problems in the construction.Based on the project of the consequent bedding rock slope on the Ramp A of Tangtun Expressway,the stability analysis and support measures of consequent bedding rock slope are studied in this paper. The main results and conclusions can be expressed as follows.(1) On the basis of investigation about the geological conditions of the consequent bedding rock slope on the Ramp A of Tangtun Expressway, analyzed the rock structure, deformation features and the major influence factors of stability and the deformation.(2)Based on the investigation about the geological conditions, the deformation mechanism of the consequent rock slope resulting from road excavation is studied. The results show that the primary failure modes of the slope are sliding and fracturing and bedding sliding. The Slope is in the initial stage of slip deformation, upper Deformation and the surface rocks slipped along the dimensions. The main reason of deformation is Broken rocks in foot and Soft interlayer between layers, rainstorm and manual excavate of at toe are induced factors.(3) Combined with the numerical calculation of the geological model of the slope, analyzed and evaluated the stability under different conditions by using limit equilibrium method. Slope is stable before the excavation, excavation make the stability of slope decreased significantly, especially in the excavation of rock in the foot and concentration of rainfall have significant Influence about the slope.(4) For the bedding rock slope deformation mechanism, taked out the emergency and long-term support program. Emergency management mainly ues the anchor frame beam to control the deformation of slope, and use monitor data as a guide, then set cable anchor piles in the foot.(5) Summarized the current situation about design cable anchor piles, and then discussed the problems in the design of anchor piles. Including the reasonability about the cable anchor piles, determined of pile spacing, the load distribution section of the form and determination of the value of cable tension.(6) With the application of pile anchors, analyzed the calculation model of anchor piles. In considering the deformation of pile anchor based on the theory of elastic foundation using anchor piles of the calculation procedure of analysis and deduction. Because of the Anchor pre-stress, changed the relationship between pile and soil interaction, should be loaded as an elastic foundation beam segment, and considered for unlimited indeterminate problem.(7) Based on monitoring data, combined with numerical simulations, the design is used anti-sliding pile with tock tendon, pre-stressed anchor cable with lattice beam and local bracing structure has confirmed validity.