Diaphragm Wall Deformation Behavior and Inclinometer Data Analysis for Braced Deep Excavations

Abstract

Concrete diaphragm walls (CDWs) are widely used as support for deep excavations in saturated soft soils with sensitive construction environments. The lateral deformation of the CDWs is typically measured by inclinometers cast in the wall. This paper discusses the evolution of the lateral deformation of the CDWs during deep excavation and the main sources of errors in inclinometer measurements. Furthermore, a correction method for the most influential errors is proposed. It is found that the multilevel supported CDWs generally experience three types of deformations during the excavation: cantilever, transition, and bulging. Accordingly, the joint error correction method for inclinometer readings can be operated efficiently to reprocess the monitored data, using total station measurement as a cross-reference. Based on the case studies of deep excavation projects located in Suzhou, China, the proposed error correction method has been demonstrated to perform satisfactorily and can assist in guiding key safety control decisions on construction sites.