Subsurface multi-physical characterization of mountain excavation and city construction in loess plateau with a fiber-optic sensing system
Subsurface multi-physical characterization of mountain excavation and city construction in loess plateau with a fiber-optic sensing system
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DOI：
10.1016/j.jrmge.2023.09.026
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发表时间：
2024-01
影响因子：
7.3
通讯作者：
Jie Liu;Bin Shi;Kai Gu;Mengya Sun;Jun-Cheng Yao;He-Ming Han
中科院分区：
文献类型：
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作者：
Jie Liu;Bin Shi;Kai Gu;Mengya Sun;Jun-Cheng Yao;He-Ming Han
在中国黄土高原启动的开山建城（MECC）项目涉及大规模人工土地的建设。了解人工土地的地下演化特征至关重要，但也具有挑战性。在这里，我们使用改进的光纤监测系统进行地下多物理表征。该系统使我们能够收集各种参数的时空分布，包括地层变形、温度和湿度。以延安新区为例，通过77米深的钻孔和30米长的沟渠进行精细化的现场监测。研究结果表明，地面沉降既涉及充填黄土的变形，也涉及下方完整黄土的变形。值得注意的是，与下面的完整黄土相比，充填黄土表现出更强的蠕变能力。变形沿剖面分布不均匀，与土壤湿度呈正相关。在充填黄土和下伏完整黄土之间的界面处观察到水积累，导致显着变形。此外，充填黄土中的温度和湿度达到了新的平衡状态，其深度分别受到大气条件的影响，测量深度分别为31 m和26 m。精细的调查使我们能够确定对新建城市地区可持续发展至关重要的关键层，并为土地创造的演变机制提供更好的见解。
Mountain excavation and city construction (MECC) projects being launched in the Loess Plateau in China involve the creation of large-scale artificial land. Understanding the subsurface evolution characteristics of the artificial land is essential, yet challenging. Here, we use an improved fiber-optic monitoring system for its subsurface multi-physical characterization. The system enables us to gather spatiotemporal distribution of various parameters, including strata deformation, temperature, and moisture. Yan'an New District was selected as a case study to conduct refined in-situ monitoring through a 77 m-deep borehole and a 30 m-long trench. Findings reveal that the ground settlement involves both the deformation of the filling loess and the underlying intact loess. Notably, the filling loess exhibits a stronger creep capability compared to underlying intact loess. The deformation along the profile is unevenly distributed, with a positive correlation with soil moisture. Water accumulation has been observed at the interface between the filling loess and the underlying intact loess, leading to a significant deformation. Moreover, the temperature and moisture in the filling loess have reached a new equilibrium state, with their depths influenced by atmospheric conditions measuring at 31 m and 26 m, respectively. The refined investigation allows us to identify critical layers that matter the sustainable development of newly created urban areas, and provide improved insights into the evolution mechanisms of land creation.