加筋煤矸石挡墙静载模型试验研究

Model Test Study on Reinforced Coal Gangue Retaining Wall Under Static Load

摘要:

为提高煤矸石利用率,减少煤矸石堆存带来的危害,探究将煤矸石作为填料用于加筋土挡墙工程的可行性及不同筋材参数对挡墙的影响。通过模型试验,对不同筋材长度(0.66H、0.99H、1.31H(H为墙高)和不同筋材强度(10、20、30 kN/m)工况下挡墙的应力及变形规律进行了研究。结果表明:挡墙承受荷载时,墙面变形自下而上逐渐增大,竖向附加应力及筋材应变均呈单峰分布,峰值点位于荷载正下方;增加筋材长度可以有效限制墙面变形和墙顶沉降,增加筋材强度有利于增强竖向应力的扩散效果;总体上,在70 kPa荷载作用下土工格栅加筋煤矸石挡墙墙面最大位移为0.1%H,墙顶沉降为0.27%H~0.45%H,且筋材应变均小于0.12%,筋土之间能够较好地相互作用,挡墙整体处于稳定状态;在实际工程中,建议筋材长度不应小于0.5H。

Abstract:

In order to improve the utilization rate of coal gangue and reduce the harm caused by coal gangue accumulation, the feasibility of using coal gangue as filler in reinforced soil retaining wall projects and the influence of different reinforcement parameters on retaining walls were explored. Through model tests, the stress and deformation laws of retaining walls under different reinforcement lengths (0.66H, 0.99H, 1.31H, where H is the wall height) and different reinforcement strengths (10 kN/m, 20 kN/m, 30 kN/m) were studied. The results show that when the retaining wall is subjected to a load, the deformation of wall surface increases gradually from bottom to top, while the vertical additional stress and the reinforcement strain show a unimodal distribution, with the peak point located directly below the load. Increasing the reinforcement length has a significant effect on limiting the lateral displacement of wall surface and the settlement at the top of the wall. Increasing the reinforcement strength is conducive to enhancing the diffusion effect of the vertical stress. Overall, under a vertical load of 70 kPa, the maximum displacement of wall surface of the geogrid-reinforced coal gangue retaining wall is 0.1%H, the settlement at the top of the wall is 0.27%H to 0.45%H, and the reinforcement strain is less than 0.12%, where the geogrid and the coal gangue achieves a good interaction, and the whole wall is in a stable state. In practical engineering, it is recommended that the length of the reinforcement be no less than 0.5H.