Original scientific paper
https://doi.org/10.15255/KUI.2015.044
Development Trend of the Compressive Strength of an In-Service Sidewall Corroded by Sulphate with a High Concentration of Ca2+
Wei He
; School of Civil and Environmental Engineering, University of Science and Technology Beijing, 100 083 Beijing, P.R. China
Xia Meng
; Architectural Design and Research Institute of Tsinghua University co., LTD, 100 084 Beijing, P.R. China
Yu Zheng
; Architectural Design and Research Institute of Tsinghua University co., LTD, 100 084 Beijing, P.R. China
Hongguang Ji
; School of Civil and Environmental Engineering, University of Science and Technology Beijing, 100 083 Beijing, P.R. China
Chengbin Liu
; Beijing Vocational College of Agriculture, Department of Hydraulic and Architectural Engineering, 102 442 Beijing, P.R. China
Abstract
At the bedrock section of the auxiliary shaft of the Tong-ting coal mine, the sidewall has varying degradation degrees in different parts. The part on which water flowed is barely corroded, whereas the moist part near the pouring joints is seriously corroded. We first studied the mechanism of this phenomenon by chromatography,
X-ray diffraction, and energy-dispersive X-ray spectroscopy. We then used simplified models built by particle flow code software (i.e., particle flow code in three dimensions, PFC3D) to analyse how increasing degradation depth affects compressive strength and failure patterns. The results were as follows. (1) Gypsum and calcite in corrosive water were supersaturated. The part on which water flowed was protected by the crystallized precipitation on the concrete. By contrast, the degradation of the part where water flowed through pouring joints was aggravated by internal crystallization and dissolution. (2) PFC3D numerical simulation indicated that decreases in vertical ultimate stress were strongly linearly correlated with degradation depth. As for the −355.5 m damaged part, reinforcement should be conducted before degradation depth reaches 250 mm. (3) No obvious signs were
observed prior to the failure of the corroded sidewall. Therefore, the development of degradation depth should be monitored before degradation parts are reinforced.
Keywords
site investigation; groundwater; degradation; failures; stress analysis
Hrčak ID:
151486
URI
Publication date:
20.1.2016.
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