| 梁多伟,罗强*,谢宏伟,刘孟适,方东.火山渣掺配土质砾砂改良填料临界动应力及累积变形特性试验研究[J].实验力学,2019,34(6):1035~1044 |
| 火山渣掺配土质砾砂改良填料临界动应力及累积变形特性试验研究 |
| Experimental study of characteristics of critical dynamic stress and accumulated deformation of volcanic slag filler improved by soil gravel sand |
| 投稿时间：2018-02-02 修订日期：2018-04-26 |
| DOI：10.7520/1001-4888-18-027 |
| 中文关键词: 火山渣填料 土质砾砂改良 动三轴试验 颗粒破碎 累积塑性应变 临界动应力 |
| 英文关键词:volcanic slag filler soil gravel sand improvement dynamic triaxial experiment particle breakage cumulatied plastic strain critical dynamic stress |
| 基金项目:国家重点基础研究发展计划(973计划)(2013CB036204);中铁二局股份有限公司科技开发计划资助项目(2013) |
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| 中文摘要: |
| 火山渣是一种颗粒形状不规则且具多孔轻质特征的粒状特殊材料，在列车动载作用下的颗粒抗破碎能力及填料的变形和强度特性是影响其作为基床填料的关键问题。为论证火山渣用于基床结构的可行性，开展了体积掺配比2∶1及3∶1火山渣掺配土质砾砂改良填料室内动三轴试验，讨论了试样制备及动载加载过程中的颗粒破碎程度，分析了动应力幅值、围压及土质砾砂掺量对改良填料动力变形特性的影响规律。试验结果表明：土质砾砂的掺入能有效地抑制火山渣在制样过程中的颗粒破碎；处于压实状态的火山渣掺配土质砾砂改良填料在长期循环荷载作用下的相对破碎率低于3%，颗粒破碎不显著。不同动应力幅值下，火山渣掺配土质砾砂改良填料的累积塑性应变曲线可分为稳定、临界和破坏型，稳定和破坏型曲线可分别采用Stewart及Monisnith模型进行预测。体积掺配比2∶1及3∶1火山渣掺配土质砾砂改良填料的临界动应力约为静强度的0.4~0.5倍，分别能满足普通II级铁路对基床表层及底层填料动力特性的要求。 |
| 英文摘要: |
| Volcanic slag filler are generally viewed as special material for their sharp edge, rough surface, porou and low quality characteristics. As a subgrade filler, its particle anti-crushing ability, the deformation and strength characteristics under dynamic load of train is the key issue. In order to verify the feasibility of volcanic slag filler used in subgrade filling, a series of dynamic triaxia lexperiments about volcanic slag filler improved by soil gravel sand at the volume mixing ratio of 2∶1 and 3∶1 were carried out, the content of particle breakage during sample preparation and dynamic stress were discussed, and also the characteristics of dynamic behavior with different dynamic stress amplitudes, confining pressure levels and content of gravely sand were analyzed. Experimental results show that the incorporation of soil gravel sand can effectively restrain the particle breakage of volcanic slag filler during sample preparation; under the long-term dynamic loading, the particle breakage index of volcanic slag filler improved by soil gravel sand in the compacted state is less than 3%, the particle breakage is not significant. The cumulative plastic strain curve can be described as stable type and the damage type under different dynamic stress amplitudes, and the curve of stable type and the damage type can be simulated by Stewart model and Monismith model respectively. The critical dynamic stress of volcanic slag filler improved by soil gravel sand at the volume mixing ratio of 2∶1 and 3∶1 were 0.40 to 0.50 time of the Static strength, which can meet the surface layer of subgrade and bottom layer of subgrade' requirement of railways grades II respectively. |
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