Journal Published Online: 28 February 2018
Volume 46, Issue 5

Modeling of Permeation and Fracturing Grouting in Sand: Laboratory Investigations



One of the significant aspects of permeation grouting is the prevention of soil fracturing during construction. In this study, a newly designed laboratory apparatus including an overburden pressure modelling system, grouting chamber, grout injection control system, back-pressure monitoring system, and high-efficiency grout mixer is developed. A wet-raining method is adopted to prepare two 45-cm-diameter, 50-cm-high, poorly graded sandy soil specimens. A bleeding test is first conducted to select a cement-bentonite mixture with minimal bleeding. A series of both water injection tests and grout injection tests are carried out to investigate the threshold seepage velocity, the fracture initiation pressure, and the factors affecting the fracture initiation pressure, using a plot of injection pressure (p) against injection rate (q). In the water injection test series, tests are repeated at two effective overburden pressures, 49 kN/m2 and 98 kN/m2, and in the grout injection test series, tests are carried out at an effective overburden pressure of 98 kN/m2. The initial orientation of the fractures and their subsequent development are mapped and discussed. In the future, the fracture initiation pressure and the threshold seepage velocity can be evaluated by reference to the p-q curve suggested in this paper using a series of modelled p-q curves for different overburden pressures. Prior to field permeation grouting work, trial grouting is deemed necessary to verify the correctness of the obtained laboratory results, in order to prevent hydrofracturing of the soil.

Author Information

Cheng, Wen-Chieh
Institute of Tunnel and Underground Structure Engineering, School of Civil Engineering, Xi’an University of Architecture and Technology, Xi’an, China
Ni, James C.
Department of Civil Engineering, National Taipei University of Technology, Taipei, Taiwan, Republic of China
Shen, Jack S.
Department of Civil and Construction Engineering, Swinburne University of Technology, Hawthorn, Victoria, Australia Department of Civil and Construction Engineering, Swinburne University of Technology, Hawthorn, Victoria, Australia
Wang, Zhi-Feng
Department of Geotechnical and Tunneling Engineering, School of Highway, Chang’an University, Xi’an, China
Pages: 16
Price: $25.00
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Stock #: JTE20170170
ISSN: 0090-3973
DOI: 10.1520/JTE20170170