This paper presents a new type of large-diameter multi-disc soil anchor and its cavity-forming tool. The large-diameter multi-disc soil anchor is obtained by adopting a toothed chain, centrifuging holes to form cavities, forming multiple cavities, placing a steel strand with centering support, injecting cement mortar, and curing. In order to study the uplift bearing characteristics and creep property of the large-diameter multi-plate soil anchor, the equal-diameter soil anchor was taken as the control group. The ultimate pull-out bearing capacity, vertical displacement, axial force, anchor plate bearing load, and side friction resistance were simulated and analyzed by FLAC3D 5.0 64-bit software, and the creep property test of the anchor bolt was carried out. The results show that under the same conditions, the ultimate pulling capacity of the large-diameter multi-disc soil anchor is 125% higher than that of the same-diameter soil anchor. The vertical displacement of the large-diameter multi-disc soil anchor decreases by 51.74% compared with that of the equal-diameter soil anchor when the ultimate uplift capacity is reached. The side friction resistance of the large-diameter multi-disc soil anchor is small and its growth rate is slow. When the ultimate pulling capacity is reached, the load sharing of the anchor disc accounts for 76.54% of the total load applied. The creep rate of the large-diameter multi-plate soil anchor bolt is 0.91 mm, and the creep rate of the equal-diameter soil anchor bolt is 1.69 mm. By fitting the data, it is found that the large-diameter multi-disc soil anchor provides a method to increase the anchorage force of the soil anchor, and the research on its bearing characteristics and creep property provides a theoretical basis for the application of the soil anchor.

Real -time monitoring of foundation pits is an important part of the engineering construction. This paper proposes a method of deformation monitoring of foundation pit based on MEMS technology. The algorithm based on time-domain integration is adopted, and a fixed distance test is designed to verify the feasibility of the algorithm. Through the indoor model test of foundation pit monitoring, MEMS sensors are embedded to collect the acceleration, rotation angle and the other signals of soil movement, and then the acceleration signal is integrated to obtain displacement by algorithm calculation. Finally, the deformation characteristics of soil in the process of foundation pit are analyzed by using soil displacement and rotation angle to investigate the effectiveness of applying MEMS technology to foundation pit monitoring. The test results show that the MEMS sensor could accurately collect the acceleration, rotation angle and other signals of soil movement in model box. The monitoring method proposed in this paper lay a theoretical foundation and experimental verification for the application of MEMS technology in foundation pit monitoring.