煤矸石风化对其物理力学性能影响的研究

Research on the effect of weathering on physical and mechanical properties of coal gangue

本文主要进行了不同风化时间的煤矸石路堤填料现场筛分试验、室内标准击实试验和抗剪强度试验.利用FLAC3D软件建立了煤矸石路堤数值分析模型,分析了不同风化时间、最佳含水量、饱水状态不同路堤高度对路堤稳定性的影响.结果表明:未风化煤矸石和经过不同风化时间的煤矸石粒径分布都不均匀,级配良好.煤矸石风化36个月后,细料含量和最大干密度均达到最大.在最佳含水量状态,随着风化时间的增加,煤矸石的黏聚力持续增加,而在饱水状态下,煤矸石的黏聚力持续降低.数值模拟结果表明:在最佳含水量状态,路堤高度相同时,随着风化时间的增加,安全系数逐渐减小.饱水状态的安全系数明显比最佳含水量状态的低.

The on-site sieve tests,indoor standard compaction tests, and shear strength tests of coal gangue with different weathering time were performed. Using the FLAC3 D software,a numerical analysis model of coal gangue embankment was established to analyze the effect of the embankment height, optimum moisture content and degree of saturation on the stability of embankment with different weathering time. The test results show that the initial coal gangue and the weathered coal gangue contain particles of strongly different grain sizes and they are denoted as well graded soils. After 36 months of weathering,the fines content and maximum dry density of coal gangue mixture reach peak values. Under the optimum moisture content, the cohesion of coal gangue increases with the increase of weathering time, while under the saturation state, the cohesion of coal gangue continues to decrease with the increase of weathering time. The numerical simulation results show that the safety factor of embankment decreases with the increase of weathering time under the optimal water content state. The safety factor in the saturated state is significant lower than that under the optimum moisture content state.