| 引用本文: | 钟嘉政,王树英,刘朋飞,王海波.泡沫改良砾砂渣土力学行为与流变模型研究[J].哈尔滨工业大学学报,2021,53(11):84.DOI:10.11918/202004085 |
| ZHONG Jiazheng,WANG Shuying,LIU Pengfei,WANG Haibo.Mechanical behavior and rheology model of foam-conditioned gravelly sand in EPB shield tunneling[J].Journal of Harbin Institute of Technology,2021,53(11):84.DOI:10.11918/202004085 |
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| 摘要: |
| 正确认识土压平衡盾构渣土力学行为特征是优化渣土改良方案、确保盾构开挖面稳定和高效掘进的重要前提,为此,针对砾砂地层盾构改良渣土,采用加压式十字板剪切仪,通过不排水侧限压缩试验,揭示泡沫改良砾砂法向压力-压缩应变的关系；通过多工况十字板剪切试验,探究泡沫改良砾砂的剪切变形全过程,分析其峰值和残余剪切强度的大小及影响因素。试验结果发现泡沫改良砾砂符合可压非牛顿流体的特征,因此,基于流变学建立泡沫改良砾砂的可压缩宾汉姆流体本构模型,拟合并分析改良土的流体压缩系数、不同法向压力下的流变参数（屈服应力、塑性黏度）,并提出其密度和峰值及残余剪切强度流变参数的压力相关性公式。研究成果可提升对带压环境下泡沫改良砾砂渣土力学行为特征的认识,并为描述盾构渣土宏观流动变形的计算流体力学数值模拟提供理论依据。 |
| 关键词: 土压平衡盾构 泡沫改良砾砂 不排水侧限压缩试验 十字板剪切试验 可压缩宾汉姆流体 |
| DOI：10.11918/202004085 |
| 分类号:TU411.3 |
| 文献标识码:A |
| 基金项目:国家重点研发计划项目(2017YFB1201204)； 湖南省研究生科研创新项目(2020zzts152) |
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| Mechanical behavior and rheology model of foam-conditioned gravelly sand in EPB shield tunneling |
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ZHONG Jiazheng1,WANG Shuying1,2,LIU Pengfei1,WANG Haibo1
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(1.School of Civil Engineering, Central South University, Changsha 410075, China; 2.Key Laboratory of Engineering Structures of Heavy Haul Railway (Central South University), Ministry of Education, Changsha 410075, China)
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| Abstract: |
| To optimize soil conditioning method and ensure the stability of excavation face and high efficiency of excavating, a good understanding of the mechanical behavior of conditioned soil in earth pressure balance (EPB) shield tunneling is essential. The pressurized vane shear apparatus was used to study the rheological behavior of conditioned soil from gravelly sand stratum. Results of undrained lateral confining compression tests revealed the relationship between the normal pressure and the compression strain of the foam-conditioned gravelly sand. Through vane shear tests, the shear deformation process of the foam-conditioned gravelly sand was investigated, and the peak and residual shear strength and corresponding effect factors were analyzed. Research results show that the foam-conditioned gravelly sand conformed to compressible non-Newtonian fluid. Therefore, constitutive model of compressible Bingham fluid for foam-conditioned gravelly sand was established based on rheology. The compressibility coefficient and rheological parameters (i.e., yield stress and viscosity) of the conditioned soil were obtained by fitting the test results. The pressure dependence formulas of density, peak and residual rheological parameters were proposed. The research can enhance the understanding of the mechanical behavior of foam-conditioned gravelly sand, and provide a theoretical basis for computational flow simulation to accurately reflect the macroscopic movements of conditioned soil in EPB shield tunneling. |
| Key words: EPB shield tunneling foam-conditioned gravelly sand undrained lateral confining compression tests vane shear tests compressible Bingham fluid |
