ISSN: 0149-6115
Published Online: 7 December 2006
Page Count: 9

Experimental Study on Fracture Behaviorqa of a Silty Clay

Wang, Jun-Jie
Associate Professor,College of River & Ocean Engineering, Chongqing Jiaotong University,Chongqing,

Zhu, Jun-Gao
Professor and Associate Professor,Research Institute of Geotechnical Engineering, Hohai University,Nanjing,

Chiu, C. F.
Professor and Associate Professor,Research Institute of Geotechnical Engineering, Hohai University,Nanjing,

Chai, He-Jun
Professor,Research & Design Institute of Chongqing Communication,Chongqing,

(Received 27 June 2006; accepted 1 November 2006)

Abstract

Fracture toughness K^IC and K^IIC are two important parameters in fracture mechanics. In this paper, a device was designed to perform improved three-point and four-point unsymmetrical bending tests on soil beams. The device can easily remove the influence of specimen self-weight on the test results. Using the improved methods and the device, K^IC, K^IIC, and mixed mode I-II stress intensity factors K^I and K^II at fracture failure of a compacted silty clay were investigated. Test results indicated that the fracture of the silty clay exhibits linear and elastic behavior. The influences of dry density, water content, and preconsolidation pressure of specimens on parameter K^IC were investigated. It was found that the classical mixed mode I-II fracture failure theories such as the strain energy density factor theory, maximum circumferential stress theory, and energy release rate theory cannot adequately predict the fracture failure behavior of the specimens, but a circle agrees well with the test results. The directions of crack growing in the specimens under mode II and mixed mode I-II loading conditions were expressed by a linear function of K^I/K^II.

Keywords:
fracture, test, soil

Paper ID: GTJ100715
DOI: 10.1520/GTJ100715
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