Research On The Flexible Design Technology Of Anti-subsidence Of Small Round Pipe Farmland Culvert

The land subsidence was caused due to the underground mining in the northern hilly area. Because of the long-time mining, complicated procedures and large mining amount, the subsidence area formed by multi-seam mining has the characteristics of more times of subsidence and longer stability time. The continuous deformation of the earth’s surface leads to a lot of problems, including the damage of farmland buildings, the loss of agricultural production and the deterioration of the peasants life, which need urgent solution.This paper took Chengzhuang Coal Mine subsidence area in Jincheng city of Shanxi Province as the research object. According to the standard of the reinforced concrete culvert design specifications and standard maps, combined with domestic and foreign mining zone culverts resistance to deformation of the special treatment and the comprehensive improvement of land influence factors survey results a farmland reinforced concrete pipe culvert technology of flexible design and scheme which can resist collapse to a certain degree was proposed in this paper. The mining subsidence and principle of finite element analysis were used in this study, based on the deformation analysis of ANSYS two-dimensional and three-dimensional finite element model in surface subsidence. This paper mainly obtains the following research results:i) The element types in the finite element model of the structure of the anti-subsidence small round pipe culvert are determined, including the pipeline unit, the soil around the pipeline and the contact element. Finally, the effective model region and boundary condition are determined.ii) The anti-subsidence small round pipe culvert technology of flexible are proposed, covering reinforced ratio, settlement joints, foundation, culvert pipe body and joint. According to the mechanical analysis method of the traditional culvert structure, the PCVX software is used to prove that the structure meets the requirements of the culvert design code under the normal condition of the foundation.iii) Applying the static analysis and the characteristic value buckling analysis to two-dimensional model of different thickness and tube type reinforced concrete pipe culvert by ANSYS, to determine the optimal scheme and the maximum bearing capacity; established a three-dimensional model of the culvert, nonlinear buckling analysis is used to simulate the culvert collapse, and analyze the stability of the structure, and puts forward the corresponding reinforcement principle. The culvert design scheme proposed can effectively adapt to the settlement of 20 cm foundation.iv)Flexible joint, four hinge culvert, flexible foundation, optimization reinforcement technology of flexible design is put forward in this paper. The scheme has the characteristics of low cost, convenient application. A full set of drawings of the flexible design technology of the reinforced concrete circular pipe culvert is given.