Abstract: Monitoring and controlling of tunneling caused ground subsidence is a key issue related to construction safety. Instead of real-time monitoring, manually measurement using total station or leveling instrument is usually conducted at regular intervals. With the rapid development of wireless sensor networks and microelectro mechanical systems, geological engineers are able to carry out a real-time wireless monitoring of ground subsidence through sensor nodes deployed on the ground. In this paper, we provide a study of accelerometer data fusion in the use of ground settlement monitoring based on surface measurements during shield tunneling. Initially, two sets of sensor nodes were placed at the surface above the excavated tunnel; after obtaining the raw data, the normal vectors of the sensors were firstly derived with the help of rotation matrices, then the dip angles over time were obtained from the projection of normal vectors in the longitudinal section; finally, a centralized Kalman filter was applied to estimate the tilt angles of the sensor nodes based on the data from two respective sets of accelerometers. Using this method, the absolute ground settlement can be achieved via a distributed deployment of sensor nodes.