破碎软岩注浆结石体的动力冲击试验及动态损伤模型辨识

发布时间：2018-07-02 06:53

  本文选题：注浆结石体 + 动力特性　； 参考：《振动与冲击》2017年10期

【摘要】：岩体注浆结石后的动力特性直接影响到岩体加固工程的动力稳定性,目前对破碎软岩注浆结石体的动力特性并不明确,因此开展结石体动力特性的定性与定量研究具有较大意义。选取典型的软岩碎块,假定注浆裂隙的均匀性并忽略浆液扩散的随机性,通过简化控制注浆模仿过程制备注浆结石体试样,借助SHPB装置进行了动态冲击压缩试验。研究结果表明,注浆结石体的破坏大部分发生在浆-岩胶结面,细观上表现出显著的脆性损伤开裂特征,宏观全应力-应变曲线初始阶段无显著的压密过程,较小应变时便达到峰值强度,但峰值强度后阶段表现出显著的应变软化特征,破坏后阶段存在一定的残余强度;软岩碎块与水泥的质量比对结石体的动力特性具有显著影响,成分最优配比条件下结石体的峰值强度可达到极大值;相同材料含量比条件下含水率越高其动峰值强度及弹性模量普遍越小,表明含水率对结石体动力特性具有显著影响。此外,基于连续损伤及统计强度理论,辨识得到了软岩注浆结石体的动态损伤力学模型及其参数,对比表明理论计算结果与实测曲线具有较好的一致性。研究成果可为开展破碎软岩注浆体的特性研究提供借鉴与参考。
[Abstract]:The dynamic characteristics of rock mass after grouting have a direct impact on the dynamic stability of rock mass strengthening project. At present, the dynamic characteristics of broken soft rock grouting stone body are not clear. Therefore, it is of great significance to carry out qualitative and quantitative study on the dynamic characteristics of stone body. The typical soft rock fragments were selected and the homogeneity of grouting cracks was assumed and the randomness of grouting diffusion was ignored. The grouting stone samples were prepared by simplified control grouting imitation process and the dynamic impact compression tests were carried out with the help of SHPB device. The results show that most of the failure of grouting stone occurs on the cementation surface of grouting rock, and it shows obvious brittle damage and cracking characteristics in meso-scale, and there is no significant compaction process in the initial stage of macroscopic total stress-strain curve. The peak strength is reached when the strain is small, but the strain softening is obvious in the post-peak strength stage, and the residual strength exists in the post-failure stage, and the mass ratio of soft rock fragments to cement has a significant effect on the dynamic characteristics of stone body. The peak strength of stone body can reach the maximum value under the condition of optimum composition ratio, and the dynamic peak strength and elastic modulus of stone body with higher water content under the same material content ratio are generally smaller, which indicates that the water content has a significant influence on the dynamic characteristics of stone body. In addition, based on the theory of continuous damage and statistical strength, the dynamic damage mechanics model and its parameters of soft rock grouting stone are identified. The comparison shows that the calculated results are in good agreement with the measured curves. The results can be used for reference in the study of grouting characteristics of broken soft rock.
【作者单位】： 福州大学土木工程学院;西华大学绿色建筑与节能重点实验室;
【基金】：国家自然科学基金(41672290) 福建省自然科学基金(2016J01189) 西华大学绿色建筑与节能重点实验室开放基金(SZJJ2016-097)
【分类号】：TU45
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本文编号：2089288