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Study of the Interface Mechanical Properties of Concrete Segments in Shield Tunnels
(1 State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan 430071; 2 Center for Geotechnical and Structural Engineering Research, Shandong University, Jinan 250061)
Abstract The interface mechanical properties of concrete segments directly affect the stress and strain of the linings in shield tunnels and further affect tunnel waterproofing performance and safety. Therefore, compression and shear tests of the concrete interface were carried out to study the mechanical properties of the interface under different normal forces, different shearing rates and cyclic shearing. The results show that:1) with an increase of normal nominal stress on the interface, its stiffness experiences exponential growth at first, then becomes stable, while the tangential friction coefficient approximately experiences a negative exponential growth; 2) with an increase of the shearing rate, the dynamic friction coefficient decreases at first and later becomes stable; and 3) during cyclic shearing, both the normal stiffness and the tangential friction coefficient of the interface exhibit stability after an increase. Based on the contact mechanics, the normal mechanical model and the tangential friction coefficient model of the interface were obtained by fitting the test results. These results can be used as a reference for the design of segment joints and force analyses of lining structures.
Abstract：
The interface mechanical properties of concrete segments directly affect the stress and strain of the linings in shield tunnels and further affect tunnel waterproofing performance and safety. Therefore, compression and shear tests of the concrete interface were carried out to study the mechanical properties of the interface under different normal forces, different shearing rates and cyclic shearing. The results show that:1) with an increase of normal nominal stress on the interface, its stiffness experiences exponential growth at first, then becomes stable, while the tangential friction coefficient approximately experiences a negative exponential growth; 2) with an increase of the shearing rate, the dynamic friction coefficient decreases at first and later becomes stable; and 3) during cyclic shearing, both the normal stiffness and the tangential friction coefficient of the interface exhibit stability after an increase. Based on the contact mechanics, the normal mechanical model and the tangential friction coefficient model of the interface were obtained by fitting the test results. These results can be used as a reference for the design of segment joints and force analyses of lining structures.
ZHAO Wu-Sheng-1,
CHEN Wei-Zhong-1,
2 etc
.Study of the Interface Mechanical Properties of Concrete Segments in Shield Tunnels[J] MODERN TUNNELLING TECHNOLOGY, 2015,V52(3): 119-126
2015, Vol. 52 