摘要:The number,scale and difficulty of underground and foundation pit projects in cities are increasing,and stricter safety and environmental requirements are being imposed on these projects.This study examined current safety and environmental protection control methods for underground and foundation pit engineering.It first analyzed safety and environmental classifications and indicators before using the principle of strength reduction to evaluate the safety of the surrounding environment of the foundation pit based on the displacement control value of the supporting structure.The safety factors of different monitoring points in the foundation pit project were evaluated based on the obtained safety factors.The safety and environmental protection indicators of underground and foundation pit engineering were addressed by the principal component analysis method using the evaluation results.These were then inputted into the BP neural network to ensure safety and environmental control during foundation pit engineering.The experimental results showed that this method can be used to control horizontal displacement and surface settlement of different monitoring points in underground and foundation pit projects,and control performance can exceed 95%.