基于黏弹塑性理论的冻结壁与井壁共同作用机理分析

发布时间：2018-05-31 05:56

本文选题：冻结法凿井 + 冻结壁　；参考：《安徽理工大学》2017年硕士论文

【摘要】：井壁冻结压力是冻结法凿井的重要技术参数,它决定冻结壁与井壁的结构设计是否科学合理,涉及施工安全。本文以位于我国淮南的杨村矿副井作为工程背景,通过理论推导、现场实测与试验相互验证的方法,探讨了井壁与冻结壁相互作用时冻结压力的分布规律。首先,根据周围土体、冻结壁及井壁相互作用机理,采用弹塑性理论得到不同DP准则下的冻结压力解析解,并分析了不同DP准则对冻结压力结果的影响。分析结果表明,在深井井壁开挖之后,冻结壁冻结压力变化规律分为快速增长、缓慢增长及逐渐稳定阶段。DP1准则屈服条件下所对应的冻结压力最大,DP5准则屈服时所对应的冻结压力最小,即利用DP1、DP3、DP4、DP6、DP2、DP5准则进行冻结壁设计时的安全性依次增强。其次,基于西原体模型流变理论,建立了冻结壁-泡沫板-外壁三维力学场模型,推导出在黏弹性与黏弹塑性两种状态下的冻结压力计算公式,对井壁设计、冻结压力计算与增长规律提供理论支撑。最后,利用现场实验结果得到计算参数,将工程实测值与理论计算结果进行对比,结果表明理论计算公式能较好描述井壁冻结压力的增长规律,证明冻结压力解析解的合理性。同时还得出,深层位井壁冻结压力发展有一个迟缓期,冻结压力随地层深度的增加而增大,同时随时间的增大而增大。通过比较可知理论计算与现场实测的冻结压力变化趋势大致相似,而两者不同之处在于冻结压力理论值到达最高峰的时间早于现场实测的冻结压力值。此外,文中还分析了平面应变解析问题的弊端。本文结论可为冻结法凿井井壁与冻结壁设计以及工程现场施工提供理论参考依据。
[Abstract]:The freezing pressure of shaft wall is an important technical parameter of freezing sinking. It determines whether the structural design of freezing wall and shaft wall is scientific and reasonable and involves the safety of construction. Taking the auxiliary well of Yangcun Mine located in Huainan of China as the engineering background, the distribution of freezing pressure in the interaction of shaft wall and frozen wall is discussed by theoretical derivation, field measurement and test. Firstly, according to the interaction mechanism of surrounding soil, freezing wall and well wall, the analytical solutions of freezing pressure under different DP criteria are obtained by using elastoplastic theory, and the influence of different DP criteria on the freezing pressure results is analyzed. The analysis results show that after deep well wall excavation, the change of freezing pressure of freezing wall is divided into rapid growth. At the stage of slow growth and gradual stabilization, the maximum freezing pressure corresponding to the maximum freezing pressure under the yield condition of the DP1 criterion is the smallest, that is, the security of the freezing wall design using DP1 / DP3 / DP4 / DP4 / DP6 / DP2 / DP5 criterion is enhanced in turn. Secondly, based on the rheological theory of Cycloplasma model, the three-dimensional mechanical field model of frozen wall, foam plate and outer wall is established, and the calculation formula of freezing pressure under two states of viscoelasticity and viscoelastic-plastic is deduced, and the shaft wall is designed. The calculation and growth of freezing pressure provide theoretical support. Finally, the calculated parameters are obtained by using the field experiment results, and the engineering measured values are compared with the theoretical calculation results. The results show that the theoretical calculation formula can better describe the growth law of the freezing pressure of the shaft wall and prove the rationality of the analytical solution of the freezing pressure. At the same time, it is also found that there is a slow period of freezing pressure development in deep wellbore. The freezing pressure increases with the increase of the depth of the layer, and increases with the increase of time. The comparison shows that the variation trend of freezing pressure between theoretical calculation and field measurement is approximately similar, but the difference between them is that the theoretical value of freezing pressure reaches the highest peak earlier than the field measured freezing pressure. In addition, the disadvantages of plane strain analysis are analyzed. The conclusion of this paper can provide a theoretical reference for the design of shaft wall and freezing wall of freezing method and the construction of engineering site.
【学位授予单位】：安徽理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD265.3

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