Groundwater leakage in shield tunnels poses a threat to the safety and durability of tunnel structures. Disturbance of adjacent constructions during the operation of shield tunnels frequently occurs in China, leading ...Groundwater leakage in shield tunnels poses a threat to the safety and durability of tunnel structures. Disturbance of adjacent constructions during the operation of shield tunnels frequently occurs in China, leading to deformation of tunnel lining and leakage in joints. Understanding the impact of adjacent constructions on the waterproofing performance of the lining is critical for the protection of shield tunnels. In this study, the weakening behavior of waterproof performance was investigated in the joints of shield tunnels under transverse deformation induced by adjacent construction. First, the relationship between the joint opening and transverse deformation under three typical adjacent constructions (upper loading, upper excavation, and side excavation) was investigated via elaborate numerical simulations. Subsequently, the evolution of the waterproof performance of a common gasket with a joint opening was examined by establishing a coupled Eulerian-Lagrangian model of joint seepage, and a formula describing the relationship between waterproof performance and joint opening was proposed. Finally, the weakening law of waterproofing performance was investigated based on the results of the aforementioned studies. It was determined that the joints with the greatest decline in waterproof performance were located at the tunnel shoulder in the upper loading case, tunnel crown in the upper excavation case, and tunnel shoulder in the side excavation case. When the waterproof performance of these joints decreased to 50% and 30%, the transverse deformations were 60 and 90 mm under upper loading, 90 and 140 mm under upper excavation, and 45 and 70 mm under side excavation, respectively. The results provide a straightforward reference for setting a controlled deformation standard considering the waterproof performance.展开更多
数字经济与实体经济融合(以下简称数实融合)已成为中国经济发展的新动力。为探究当前中国数实融合发展的现状和区域差异,首先在剖析数实融合发展内涵及机理的基础上,从融合条件、融合应用、融合效益三个维度构建评价指标体系,其次利用...数字经济与实体经济融合(以下简称数实融合)已成为中国经济发展的新动力。为探究当前中国数实融合发展的现状和区域差异,首先在剖析数实融合发展内涵及机理的基础上,从融合条件、融合应用、融合效益三个维度构建评价指标体系,其次利用纵横向拉开档次法对中国30个省区市2013—2020年数实融合发展水平进行测度,最后结合基尼系数与探索性空间数据分析法(exploratory spatial data analysis,ESDA)研究区域间融合发展的时空差异。实证研究结果表明:近几年中国数实融合发展水平持续上升,整体具有向好的发展态势;区域间发展差异明显,发展水平从东向西依次递减,融合发展水平最高的是广东,最低的是青海;在发展过程中,融合应用能力不足是制约发展的关键原因且地域间缺乏融合互动,在空间上表现出明显的正向集聚特征。本研究从战略指引、应用强化和区域合作等方面提出对策建议,可为各部门制定数实融合发展的相关计划提供参考。展开更多
基金The present study was conducted with the support of the Youth Science and Technology Innovation Talent Project of Hunan Province(No.2021RC3043)National Natural Science Foundation of China(Grant Nos.52090082,51878267,52122807,and 51938005)the High-level Talent of Innovative Research Team of Hunan Province,China(No.2019RS1030).We gratefully acknowledge their financial support.
文摘Groundwater leakage in shield tunnels poses a threat to the safety and durability of tunnel structures. Disturbance of adjacent constructions during the operation of shield tunnels frequently occurs in China, leading to deformation of tunnel lining and leakage in joints. Understanding the impact of adjacent constructions on the waterproofing performance of the lining is critical for the protection of shield tunnels. In this study, the weakening behavior of waterproof performance was investigated in the joints of shield tunnels under transverse deformation induced by adjacent construction. First, the relationship between the joint opening and transverse deformation under three typical adjacent constructions (upper loading, upper excavation, and side excavation) was investigated via elaborate numerical simulations. Subsequently, the evolution of the waterproof performance of a common gasket with a joint opening was examined by establishing a coupled Eulerian-Lagrangian model of joint seepage, and a formula describing the relationship between waterproof performance and joint opening was proposed. Finally, the weakening law of waterproofing performance was investigated based on the results of the aforementioned studies. It was determined that the joints with the greatest decline in waterproof performance were located at the tunnel shoulder in the upper loading case, tunnel crown in the upper excavation case, and tunnel shoulder in the side excavation case. When the waterproof performance of these joints decreased to 50% and 30%, the transverse deformations were 60 and 90 mm under upper loading, 90 and 140 mm under upper excavation, and 45 and 70 mm under side excavation, respectively. The results provide a straightforward reference for setting a controlled deformation standard considering the waterproof performance.
文摘数字经济与实体经济融合(以下简称数实融合)已成为中国经济发展的新动力。为探究当前中国数实融合发展的现状和区域差异,首先在剖析数实融合发展内涵及机理的基础上,从融合条件、融合应用、融合效益三个维度构建评价指标体系,其次利用纵横向拉开档次法对中国30个省区市2013—2020年数实融合发展水平进行测度,最后结合基尼系数与探索性空间数据分析法(exploratory spatial data analysis,ESDA)研究区域间融合发展的时空差异。实证研究结果表明:近几年中国数实融合发展水平持续上升,整体具有向好的发展态势;区域间发展差异明显,发展水平从东向西依次递减,融合发展水平最高的是广东,最低的是青海;在发展过程中,融合应用能力不足是制约发展的关键原因且地域间缺乏融合互动,在空间上表现出明显的正向集聚特征。本研究从战略指引、应用强化和区域合作等方面提出对策建议,可为各部门制定数实融合发展的相关计划提供参考。
