การพัฒนาแบบจำลองทางคณิตศาสตร์สำหรับพฤติกรรมการคืบของหินดินเหนียวจากเหมืองถ่านหินแม่เมาะ

Abstract

Mae Moh Coal Mine is the largest open-pit mine in Thailand. Nowadays, the mine is continuing mining operations with higher depth of more than 300 meters in the future. Therefore, the long-term stability associated with the creep behavior of the claystone which is the main component of Mae Moh mine slopes must be seriously considered. Creep is a time-dependent behavior of a material under the condition of constant stress for a curtain time period. This paper aimed to develop a mathematical model of creep behavior of Mae Moh claystone based on the specially customized multi-stage creep tests. With the help of microscopic tests, the properties of claystone will be better interpreted. XRF, XRD, FT-IR and SEM tests revealed that the calcite 42.2%, quartz 37.5%, kaolinite 17.5%, and pyrite 2.9%. The creep mathematical models were used to simulate the creep behavior of Mae Moh claystone under a range of stress conditions of the Mae Moh mine. Four models of Maxwell model, Kelvin model, Kelvin-Voigt model and Bugers Creep model were proposed in this study. The result showed that the Bugers Creep model had a good agreement between the test results and a model. This could be used to describe the creep behavior of Mae Moh claystone.