The increasing severity of ground subsidence, ground fissure and other disasters caused by the excessive exploitation of deep underground resources has highlighted the pressing need for effective management. A significant contributing factor to the challenges faced is the inadequacy of existing soil mechanics experimental instruments in providing effective indicators, creating a bottleneck in comprehensively understanding the mechanisms of land subsidence. It is urgent to develop a multi-field and multi-functional soil mechanics experimental system to address this issue. Based soil mechanics theories, the existing manufacturing capabilities of triaxial apparatus and the practical demands of the test system, a set of multi-field coupled high-pressure triaxial system is developed tailored for testing deep soils (at depths of approximately 3 000 m) and soft rock. This system incorporates specialized design elements such as high-pressure chamber and horizontal deformation testing devices. In addition to the conventional triaxial tester functions, its distinctive feature encompass a horizontal deformation tracking measuring device, a water release testing device and temperature control device for the sample. This ensemble facilitates testing of horizontal and vertical deformation water release and other parameters of samples under a specified stress conditions, at constant or varying temperature ranging from −40°C–90°C. The accuracy of the tested parameters meets the requirements of relevant current specifications. The test system not only provides scientifically robust data for revealing the deformation and failure mechanism of soil subjected to extreme temperature, but also offers critical data support for major engineering projects, deep exploration and mitigation efforts related to soil deformation-induced disaster.

Groundwater exploitation has been regarded as the main reason for land subsidence in China and thus receives considerable attention from the government and the academic community. Recently, building loads have been identiied as another important factor of land subsidence, but researches in this sector have lagged. The efect of a single building load on land subsidence was neglected in many cases owing to the narrow scope and the limited depth of the additional stress in stratum. However, due to the superposition of stresses between buildings, the additional stress of cluster loads is greater than that of a single building load under the same condition, so that the land subsidence caused by cluster loads cannot be neglected. Taking Shamen village in the north of Zhengzhou, China, as an example, a finite-difference model based on the Biot consolidation theory to calculate the land subsidence caused by cluster loads was established in this paper. Cluster loads present the characteristics of large-area loads, and the land subsidence caused by cluster loads can have multiple primary consolidation processes due to the stress superposition of diferent buildings was shown by the simulation results. Pore water migration distances are longer when the cluster loads with high plot ratio are imposed, so that consolidation takes longer time. The higher the plot ratio is, the deeper the effective deformation is, and thus the greater the land subsidence is. A higher plot ratio also increases the contribution that the deeper stratigraphic layers make to land subsidence. Contrary to the calculated results of land subsidence caused by cluster loads and groundwater recession, the percentage of settlement caused by cluster loads in the total settlement was 49.43% and 55.06% at two simulated monitoring points, respectively. These data suggest that the cluster loads can be one of the main causes of land subsidence.

Based on the formation and development analysis of the environmental geological disaster of land subsidence, earth fissures and other geological disasters in the North China，it showed these disasters caused a very serious problem in some areas of the North China, such as the deep groundwater exploitation cone, which is accumulated with great damage and loss and is hard to be controlled, therefore, great attention should be paid. It is considered that the formation of the deep groundwater cone is the root of various geological environmental problems, and the groundwater cone recovery is the key to solve other environmental problems.