论文部分内容阅读
研究目的:本文通过研究泥水在地层中的劈裂和伸展现象,给出一种地层劈裂抗力的测定方法,从而为泥水盾构掘进过程中泥水压力设定提供参考,防止盾构掘进过程中泥水喷发现象的发生。创新要点:1.给出了地层劈裂抗力的测定方法,并通过现场试验和理论分析得出该方法是可靠的;2.建立了考虑泥水粘性和比重的地层劈裂伸展模型,该模型对现场试验结果有较好的预测;3.结合地层劈裂抗力和泥水劈裂伸展特性给出了盾构掘进过程中泥水压力的设定上限。研究方法:基于现场泥水劈裂试验,通过试验结果分析和理论分析,建立了劈裂压力和劈裂伸展压力的计算模型。通过泥水和地层参数对计算模型的影响分析,给出泥水盾构掘进过程中泥水配比和压力设定选择建议。重要结论:1.本文描述的现场泥水劈裂仪可以用于地层劈裂抗力的测定;2.使用总应力法的劈裂模型能够很好的预测地层的初始劈裂压力;3.考虑泥水粘性和比重的地层劈裂伸展模型对现场试验结果有较好的预测;4.在劈裂伸展的过程中,具有更大比重和粘性的泥水有利于阻止劈裂的进一步伸展,但是对初始劈裂压力的影响不大。5.在实际盾构掘进过程中,泥水劈裂发生后很难阻止其伸展。因此,防止泥水喷发的关键措施在于设定泥水压力上限防止泥水劈裂。
Research purposes: In this paper, by studying the phenomenon of splitting and spreading of muddy water in the stratum, a method for measuring the splitting resistance of the stratum is given, which can provide a reference for setting the pressure of muddy water in shield tunneling, The occurrence of muddy water eruption phenomenon. The main points of innovation are as follows: 1. The determination method of formation splitting resistance is given, and the method is reliable by field test and theoretical analysis. 2. The formation splitting extension model considering the muddy water viscosity and specific gravity is established. Field test results have a better prediction; 3. Combined with formation splitting resistance and mud splitting extension characteristics of the shield tunneling process set the upper limit of the muddy water pressure. Research Methods: Based on the field mud-water splitting test, the calculation model of splitting pressure and splitting extension pressure was established through the analysis of test results and theoretical analysis. Based on the analysis of the influence of the parameters of muddy water and formation on the calculation model, the suggestions for setting the muddy water ratio and pressure during the shield tunneling are given. The main conclusions are as follows: 1. The on-site mud splitting instrument described in this article can be used for the determination of formation splitting resistance. 2. The splitting model using the total stress method can predict the initial splitting pressure of the strata well.3. And the specific gravity of the formation splitting stretch model for the field test results have a better prediction; 4. In the splitting stretch process, with greater specific gravity and viscosity of the mud water is conducive to prevent the further propagation of splitting, but the initial splitting Little effect of pressure. 5. In the actual shield tunneling process, it is difficult to prevent the spread of mud splitting. Therefore, the key measure to prevent muddy water eruption is to set the upper limit of mud pressure to prevent mud splitting.