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高速公路路基岩溶塌陷通常可以采用水平加筋体防治,系统地研究其受力特性及设计理论具有重要的工程意义和实际价值。首先,针对公路路基荷载及岩溶塌陷的特点,分析了塌陷坑上方水平加筋体的受力和传力特性,采用太沙基土拱理论,计算溶洞上方荷载。深入探讨了水平加筋体设计方法,认为锚固段端部加筋体应变及锚固段传力长度是设计中的关键值,且其与锚固段端部加筋体拔出量密切相关。然后,引入水平加筋体与土体界面的线弹性-全塑性模型,由基本方程导出锚固段水平加筋体弹塑性解答,并结合边界条件建立了锚固段端点拔出量及传力长度的解算流程。在此基础上,引入某实际工程计算参数进行分析,将该方法结果与基于全塑性模型的分析结果进行对比,探讨了不同临空段宽度、加筋体刚度、上覆土体高度、界面摩擦角等因素对临空段端部拔出量计算误差的影响,并分析了上覆土体高度与锚固段传力长度之间的关系。由分析可知,基于线弹性-全塑性模型计算的拔出量和传力长度均较全塑性模型计算结果大,某些情况下,传力长度的计算误差高于40%,若采用全塑性模型计算有可能引起较大的误差,导致设计偏于不安全。
The subgrade karst collapse of the highway can usually be controlled by the horizontal reinforcement body. It is of great engineering significance and practical value to systematically study its stress characteristics and design theory. First of all, according to the characteristics of highway embankment load and karst collapse, the force and force transmission characteristics of horizontally stiffened body above the collapse pit are analyzed. The terrestrial arch theory of Tai Sha Ji is used to calculate the load above the karst cave. The design method of horizontal stiffened body is discussed in depth. It is considered that the strain of the stiffened body at the end of anchorage section and the force transmission length of the anchored section are the key values in the design, and are closely related to the pullout of the stiffened body at the end of the anchored section. Then, by introducing the linear elastic - all plastic model of the interface between horizontal stiffened body and soil, the elastic-plastic solution of the horizontal stiffened body in the anchored section is derived from the basic equations, and the amount of end-point pullout and the length of the force transmitted in the anchored section are established according to the boundary conditions Solve the process. Based on this, the actual engineering calculation parameters are introduced for analysis, and the results of the method are compared with the analysis results based on the all plasticity model. The effects of different sections of aeroengine on the width, stiffness of stiffened body, overburden height, interface frictional angle And other factors on the calculation error of the pull-out of the end of the empty section, and analyzes the relationship between the height of the overlying soil and the force transmission length of the anchorage section. From the analysis, it can be seen that the pull-out amount and force-carrying length calculated based on the linear elastic-all-plastic model are all larger than those calculated by the all-plastic model. In some cases, the calculation error of the transmission force length is higher than 40% Calculation may cause a larger error, resulting in the design partial to insecurity.