RESEARCH ARTICLE


Selective Tests of Grouting Material for Fractured Coal and Rock Masses in a Water-borne H2S Environment



Peili Su1, *, Zhengfan Wei2
1 Xi’an University of Science and Technology, Xi’an 710054, Shaanxi, China
2 Shaanxi Provincial Expressway Construction Group Co., Xi’an 710054, Shaanxi, China


© 2017 Su and Wei

open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: https://creativecommons.org/licenses/by/4.0/legalcode. This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

* Address correspondence to this author at the School of Architecture and Civil Engineering, Xi’an University of Science and Technology Yan Ta Street, Xi'an 710054, China; Tel: 13659119857; Fax: 86-29-85583153; E-mail: supeili824@163.com


Abstract

Coal mining is vulnerable to multiple kinds of threat from water incursion. Many coal seams contain dissolved H2S, which may be released during mining, seriously endangering the health of workers. Orthogonal testing was used to analyze the physical and mechanical properties of composite slurries in different proportions. The results showed slurry with a water-solid ratio of 0.8:1 to have the optimal combination of properties. A uniform experimental method was used to investigate the impact of the water-cement ratio, concentration of sodium silicate, and volume of cement-sodium silicate (CS) on the setting time and consolidating strength of CS slurry. This paper provides the appropriate application scope of two grouting materials (optimized composite slurry and CS slurry), based on experimental data and the results of a large number of in situ trials. Finally, the optimized composite slurry and cement-sodium silicate slurry were used to carry out grouting of the center auxiliary transport roadway of the 3−1 coal seam at the Ningtiaota Coal Mine, operated by the Shaanxi Coal Industry Group. It was shown that the type and formula of the slurry could be changed in a timely manner, based on the water outlet and concentration of H2S at the site, achieving successful grouting reinforcement and seepage-proofing.

Keywords: Water-borne H2S environment, Fractured coal and rock masses, Composite slurry, Optimized design, Cement-sodium silicate slurry, Optimization formula test, Engineering application.