超高水充填材料侧限压缩应力应变本构关系研究

A constitutive model of superhigh-water filling material under confined compression

开展超高水充填材料应力应变关系研究对准确了解充填体与围岩相互作用关系,选取合理的采煤工作面采空区充填体强度和材料配比具有重要意义。根据不同经典理论模型的本构关系特征,结合常用的3种水灰比超高水充填材料在侧限压缩条件下的应力应变曲线,获得了材料变形过程信息。基于Poyting-Thomson模型,引入损伤变量,构建出可描述超高水充填材料应力应变关系的M|D|H理论模型,并给出了理论模型的解析解,对试验全过程曲线进行辨识,确定了模型中的相关参数,实现了对超高水充填材料变形过程的理论描述。结果表明:改进的Poyting-Thomson模型(M|D|H模型)理论值与试验结果吻合较好,能够有效描述侧限压缩条件下超高水充填材料从弹性变形到应变软化再到应变硬化的整体变形特征。

The study on the stress-strain relationship of superhigh-water filling material is significant in understanding the interaction between the filling body and surrounding rock,and in selecting reasonable strength of the filling body and material ratios in the working face.According to the law and characteristic of different classical theory models,combined with the tested constitutive curves of three material ratios of superhigh-water filling material that are commonly used in engineering under confined compression,the deformation characteristics of the superhigh-water filling material have been obtained.On the basis of the Poyting-Thomson model,damage variable has been introduced to establish a M|D|H theory model which can tell the stress-strain relationship of superhigh-water filling material,meanwhile corresponding analytic solutions for the M|D|H model has been put forward.And then parameters fitting to this model have been determined by analyzing the experimental constitutive curves.The establishment of M|D|H model has realized theoretical simulation to the deformation of superhigh-water filling material.The results have shown that the improved Poyting-Thomson model(M|D|H model)can effectively describe the overall deformation characteristics of superhigh-water filling material from elastic deformation to strain softening and strain hardening under condition of confined compression.