Theoretical And Applied Research On Post-Panel Bolts Structure's Retaining Of Cutting Slopes On Expressway

Most mountain and hill terrain in our western China has complicated topographical and hydrogeological conditions which always cause high and steep cutting slopes in the expressway's designing and construction. Because internal stresses of the slopes are changed by massive trenches, there are many geological disasters occurring such as slope's collapses and landslides etc. Therefore, how to protect and avoid such disasters effectively has an important practical significance in engineering.Firstly, combined with slope features of highways and based on synthetic analysis of research findings by the others on cutting slopes of expressway, the thesis deeply investigates the usual destroying modes and their main influenced factors of high and steep slopes and systematically concludes various protecting and strengthening technology of high and steep cutting slopes, and synthetically analyses and summarizes the commonly-used analytical methods of stability of slopes through out the world. Then, considering the post-panel bolts structure as its main research object, the thesis studies on the strengthening theory and the designing calculation methods of the structure. As the anti-pulling force calculation formulas of grouting bolts are complicated and inconsistent, it brings forth an unified calculation formula on the basis of anti-pulling force calculation equations used in tribological grouting bolts and widened hole bolts with the consideration of various influenced factors of soil layers and rock layers. At last, combined with the construction of Xiang-Lei expressway it puts the unified calculation formula into the practical treating engineering of cutting slopes there. Through the stability analysis of typical section on engineering by using SLOPE procedure and analogical assessment of treating results by using ANSYS finite element procedure, it supplies technological supports to the protecting and strengthening designing of engineering, gains beneficial economical and social efficiency and a series of conclusions which have a conducting significance on the analogous cases of slopes treating and protecting engineering.