Stability Analysis Model of Expressway Passing through Goaf Based on SBAS-InSAR Technology

Abstract

Due to the lack of historical subsidence data on goaf sites alongside expressways, it is difficult to comprehensively evaluate the stability of goaf sites and accurately identify potential risk points. An investigation to study the stability of goaf sites in the Huaibei section of the Xu Huaifu Expressway is conducted through SBAS-InSAR technology and field investigation. Initially, the stability of the goaf site around the route is anticipated through field investigation. Afterwards, based on the extraction of Sentinel-1 satellite images, subsidence data of the goaf sites from 2017 to 2021 were extracted. Finally, the stability of risk points is analysed. Results demonstrate that although mining in the area stopped more than five years ago, the goaf site has continued to slowly sink. According to four years of goaf site subsidence data extracted by SBAS-InSAR technology, two subsidence risk areas, namely, Y1-05 and Y1-09, were discovered, and the subsidence areas displayed an obvious inverted “convex” shape. Of these two areas, Y1-05 is a potential risk point that was not found during the field investigation. The subsidence basin in the Y1-05 area has developed gradually, and the residual subsidence is expected to be close to 475 millimetres within the next 15 years. Although it can be considered a stable area, the subsidence value is quite large and may pose risks to route safety. Therefore, a flexible reinforced mesh can be adopted for the route. The subsidence basin of Y1-09 is the largest, but the expected residual subsidence is only 50 millimetres and will have insignificant influence on the route. Engineering practice shows that SBAS-InSAR technology can effectively analyse the surface deformation of goaf sites and has important practical significance in optimising the selection of special geological routes in expressways.

Review of Sensor-Based Subgrade Distress Identifications

“…Ground-penetrating radar (GPR) [22][23][24][25][26] Total station [27][28][29][30][31] InSAR [32][33][34][35][36] Distributed optical fiber [37][38][39][40][41] Subgrade frost heaving Ground-penetrating radar (GPR) [42][43][44][45] Multi-sensor embedding [46][47][48][49][50] Weak subgrade Falling weight deflectometer (FWD) [51][52][53][54][55][56]…”

“…Shi Min et al [40] pointed out that InSAR technology has been successfully used to study the long-term micro-deformation of linear characteristics under all terrain conditions and large spatial scales. Tao Wenbin et al [41] investigated the stability of an expressway goaf using InSAR technology and field investigation. Initially, the stability of the goaf around the route was predicted through field investigation.…”

Stability evaluation of goaf in closed mining area: a case study of Sanhejian closed mining area in Jiangsu Province, China

“…Wu (Wu et al 2018) similarly conducted a fuzzy comprehensive evaluation of the ground stability of the goaf and effectively validated it based on actual site conditions. Current research on goaf stability mostly focuses on pre-mining or during mining stages (Cai et al 2021;Tao et al 2022), while the closure of coal mines, due to complex and unknown underground conditions, cannot be continuously monitored, leading to limited research on goaf stability in closed coal mines, which requires further exploration. This paper evaluates the stability of goaf areas within closed coal mines through a combination of comprehensive numerical simulation and AHP-based Vulnerability Index.…”