改性煤矸石在矿区重载道路中的应用研究

发布时间：2018-07-11 09:36

本文选题：矿区道路 + 重载　；参考：《中国矿业大学》2015年硕士论文

【摘要】：本文以矿区运煤道路现状为背景,结合矿区煤矸石资源丰富的条件,提出采用石灰、粉煤灰、水泥等结合料对煤矸石进行改性,使其代替道路常规使用的基层、底基层,并使其能够满足矿区道路超重载的行车条件。本文通过将理论计算、改性煤矸石实验室试验以及数值模拟相结合的方法,得到了改性煤矸石处理路基时路基当量回弹模量的变化规律、弯沉值在不同改性煤矸石底基层厚度及模量条件下的变化规律,并对煤矸石进行了改性试验,得到不同风化程度下其物理力学参数的变化规律,基于试验结果建立有限元模型,在弯沉及应力等效条件下对矿区重载道路进行组合设计,获得了以下主要成果:(1)路基当量回弹模量随改性煤矸石处理层厚度及模量的增大而增大,但随着其模量的增加,路基当量回弹模量增加的趋势逐渐变缓。得到路基当量回弹模量增加到120MPa、150MPa、180MPa及200MPa时,所需改性煤矸石处理层厚度及模量的组合。在路基当量回弹模量及底基层一定时,弯沉值随轮压的增加而增加,在路基当量回弹模量及轮压一定时,弯沉值随改性煤矸石底基层厚度的增大而减小,同时随改性煤矸石底基层模量的增大而减小。得到基于弯沉等效条件下,路基当量回弹模量取120MPa、150MPa、180MPa及200MPa时,不同轮压条件下所需改性煤矸石底基层的厚度与模量的组合设计依据;(2)通过实验室试验,得到改性煤矸石7d无侧限抗压强度,均满足重载道路结构层底基层填筑材料的要求。由试验结果可知,水泥稳定煤矸石强度早期发展较快,增长趋势随时间逐渐变缓,而石灰粉煤灰稳定煤矸石强度早期强度发展较慢,后期强度增长较快;得出采用不同风化程度下的改性煤矸石处理路基时,路基当量回弹模量与处理层厚度及模量的关系,同时利用劈裂试验得到其粘聚力和内摩擦角,为有限元分析提供必要的物理参数;(3)利用ANSYS有限元软件,在弯沉等效的条件下,在采用改性煤矸石处理路基基础上,改性煤矸石做底基层时优化道路结构层与原道路结构层各层的弯拉应力进行了分析。通过分析可知,优化道路结构层各层弯拉应力均小于原道路结构层各层弯拉应力,并得到将路基当量回弹模量提高后,在弯沉及应力等效条件下,改性煤矸石底基层厚度及模量组合不同时道路结构所能承受的最大荷载;(4)通过有限元分析,提出了在不同轮压条件下矿区重载道路的设计依据。
[Abstract]:In this paper, the coal gangue is modified with lime, fly ash, cement and other binders to replace the basic course and the bottom base, which are used in the road, based on the present situation of coal transportation road in the mining area and the condition of abundant coal gangue resources in the mining area, such as lime, fly ash, cement and so on. It can satisfy the driving condition of road overload in mining area. Through the combination of theoretical calculation, laboratory test of modified coal gangue and numerical simulation, the variation law of equivalent modulus of resilience of roadbed treated by modified gangue is obtained in this paper. The variation law of deflection value under the condition of different thickness and modulus of coal gangue base is studied, and the change law of physical and mechanical parameters of coal gangue under different weathering degree is obtained. The finite element model is established based on the test results. Under the condition of deflection and equivalent stress, the main results are as follows: (1) the equivalent elastic modulus of roadbed increases with the thickness and modulus of the modified coal gangue treatment layer, but increases with the increase of its modulus. The increasing trend of the equivalent modulus of resilience of subgrade gradually becomes slower. When the equivalent modulus of resilience of roadbed is increased to 120 MPA and 200 MPA, the thickness and modulus of the modified coal gangue treatment layer are obtained. The deflection value increases with the increase of the wheel pressure when the equivalent modulus of springback of the subgrade and the base of the subgrade are fixed, and the deflection value decreases with the increase of the thickness of the base of the modified coal gangue when the equivalent modulus of springback and the wheel pressure of the roadbed are fixed. At the same time, the modulus of the modified coal gangue base decreases with the increase of the base modulus. Under the equivalent condition of deflection, when the equivalent modulus of resilience of roadbed is 120 MPA ~ 150 MPA ~ 180 MPA and 200 MPA, the combined design basis of thickness and modulus of modified coal gangue base is obtained under different wheel compression conditions. (2) through laboratory test, The unconfined compressive strength of modified coal gangue for 7 days is obtained, which can meet the requirements of filling materials for the base course of heavy load road structure layer. According to the test results, the strength of cement stabilized gangue develops rapidly in the early stage, and the increasing trend becomes slower with time, while the strength of coal gangue stabilized by lime and fly ash develops slowly at the early stage and the strength increases faster at the later stage. The relationship between the equivalent resilience modulus of roadbed and the thickness and modulus of the treated layer is obtained when the modified coal gangue is used to treat the roadbed with different weathering degree. The cohesion and internal friction angle of the roadbed are obtained by splitting test. It provides necessary physical parameters for finite element analysis. (3) using ANSYS finite element software, under the condition of equivalent deflection, on the basis of using modified coal gangue to treat roadbed, The bending tensile stress of the road structure layer and the original road structure layer is analyzed when the modified coal gangue is used as the base course. The results show that the bending tensile stress of each layer of the optimized road structure layer is smaller than that of the original road structure layer, and the equivalent elastic modulus of the roadbed can be increased under the condition of deflection and equivalent stress. The maximum load that the road structure can bear when the thickness and modulus of the modified coal gangue base is different; (4) through the finite element analysis, the design basis of heavy load road in mining area under different wheel compression conditions is put forward.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U421.6;U414

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