An Investigation into the Performance of Excavation with Inclined Struts Connected to Adjacent Buildings

Document Type : Regular Paper


1 Department of Civil Engineering; Islamic Azad University, Karaj Branch, Karaj, Iran

2 Department of Civil Engineering, University of Tehran, Tehran, Iran


One practical excavation support system is the inclined struts connected to adjacent buildings. This method is very common in small excavations, because of simplicity and minimum cost, when soil is cohesive and depth of excavation is less than stability depth (Hcr) but adjacent structures is at risk of damage due to weakness, old age or lack of proper skeleton frame. Although this method has been used in many small excavations, it is not entirely investigated. This study describes the performance of struts based on field observations and the results of numerical analysis. A small strain constitutive model (Duncan-Chang) was used for analysis. The efficiency of struts was evaluated by comparing the movements of the real case of excavation with struts and the same case but without struts. The results indicate that movements are decreased substantially using struts. A mechanism of struts during excavation is proposed and the effect of installation of the inclined strut on deformation patterns is discussed. The study introduces simple instrumentation designed in the course of the study that can be used in common engineering practice for small to medium-sized excavations.


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