Abstract

Rock mechanical property testing under high-temperature true triaxial compression conditions is significantly important to understanding the stability of deep underground engineering rock masses where high temperature exists. This article presents the development, calibration and application of a self-designed true triaxial test system for investigating rock mechanical behaviors under coupled high-temperature and high-pressure conditions with cuboid rock samples. The test system is consisted of four independent parts, respectively for mechanical loading in three axis, thermal loading up to 250 °C, deformation and temperature measurement, and the data acquisition center. The key technology and calibration method of the measurement sensors were introduced. The primary testing results of Jinping marble, Bayu granite and Longchang sandstone under high-temperature and high-pressure coupled true triaxial conditions were obtained. It shows that the peak strength, elastic modulus and fracture mode vary with rock types and temperatures. The mechanical property of Jinping marble increases with the increase of temperature in the tested temperature range, while Longchang sandstone shows a decreasing trend, and the change of Bayu granite is relatively small. The fracture mode of Jinping marble, Bayu granite Longchang sandstone at different temperatures is compressive-shear fracture. The results verify the reliability of the test system, and provides a new platform for understanding the mechanical properties of rocks of deep underground engineering with high temperatures.

摘要

高温真三轴压缩条件下的岩石力学性能测试对于了解存在高温的深层地下工程岩体的稳定性具有重要意义。本文介绍了自主设计的真三轴试验系统的开发、标定和应用，用于研究长方体岩石样品在高温高压耦合条件下的岩石力学行为。测试系统由四个独立的部分组成，分别为三轴机械加载、高达250℃的热加载、变形和温度测量以及数据采集中心。介绍了测量传感器的关键技术和标定方法。锦屏大理石初步检测结果，获得了高温高压耦合真三轴条件下的巴渝花岗岩和隆昌砂岩。结果表明，峰值强度、弹性模量和断裂模式随岩石类型和温度而变化。锦屏大理岩的力学性能在测试温度范围内随温度的升高而升高，而隆昌砂岩呈下降趋势，巴渝花岗岩的变化相对较小。锦屏大理岩、巴渝花岗岩隆昌砂岩在不同温度下的断裂方式为压剪断裂。研究结果验证了该试验系统的可靠性，为了解深部地下高温工程岩石力学特性提供了新的平台。结果表明，峰值强度、弹性模量和断裂模式随岩石类型和温度而变化。锦屏大理岩的力学性能在测试温度范围内随温度的升高而升高，而隆昌砂岩呈下降趋势，巴渝花岗岩的变化相对较小。锦屏大理岩、巴渝花岗岩隆昌砂岩在不同温度下的断裂方式为压剪断裂。研究结果验证了该试验系统的可靠性，为了解深部地下高温工程岩石力学特性提供了新的平台。结果表明，峰值强度、弹性模量和断裂模式随岩石类型和温度而变化。锦屏大理岩的力学性能在测试温度范围内随温度的升高而升高，而隆昌砂岩呈下降趋势，巴渝花岗岩的变化相对较小。锦屏大理岩、巴渝花岗岩隆昌砂岩在不同温度下的断裂方式为压剪断裂。研究结果验证了该试验系统的可靠性，为了解深部地下高温工程岩石力学特性提供了新的平台。锦屏大理岩的力学性能在测试温度范围内随温度的升高而升高，而隆昌砂岩呈下降趋势，巴渝花岗岩的变化相对较小。锦屏大理岩、巴渝花岗岩隆昌砂岩在不同温度下的断裂方式为压剪断裂。研究结果验证了该试验系统的可靠性，为了解深部地下高温工程岩石力学特性提供了新的平台。锦屏大理岩的力学性能在测试温度范围内随温度的升高而升高，而隆昌砂岩呈下降趋势，巴渝花岗岩的变化相对较小。锦屏大理岩、巴渝花岗岩隆昌砂岩在不同温度下的断裂方式为压剪断裂。研究结果验证了该试验系统的可靠性，为了解深部地下高温工程岩石力学特性提供了新的平台。