三维地应力测试系统及其在深部软岩中的应用研究

深部围岩大多软弱破碎,传统地应力测试方法难以成功实施。为满足深部软岩工程需要,采用基于流变应力恢复理论的三维测试系统进行地应力测试。该系统根据深部软岩在高应力下的强流变特点,辅以配套研发的孔内推送设备和数据采集装置,采用埋设压力传感装置的方法来测得岩体的应力状态。依托平煤五矿开展测试系统的试点应用,与空心包体应变计测试结果进行对比,并在十一矿实施了分布式工程应用。结果表明系统测得应力相较对比测值基本一致,且符合孔周岩体流变应力恢复规律,所选测试区域自重应力场均占有主导地位。因此可以说明测试结果准确有效,系统具备一定的长期稳定监测围岩应力场的能力。

Three-dimensional Test System of Geostress and its Practical Research in Deep Soft Rock

Deep surrounding rock is weak and broken mostly. Traditional geostress measurement methods are hard to implement there. To meet the needs of deep engineering in soft rock, three-dimensional test system is used, based on rheological stress recovery method. Due to strong rheological characteristics of the rock under high stress, the system measures stress state of rock through embedding pressure-sensing device by using push equipment in borehole and data collector. Relying on Pingdingshan No.5 coal mine, pilot test is applied, compared with the test via hollow inclusion cells. And distribution test is applied in No.11 coal mine. The results show that measured stress is essentially identical with contrast value and conforms the rule of rheological stress recovery. Self-weight stress field is dominant in all test area. Thus the results are considered as accurate, and the system can monitor stress field of surrounding rock long-termly and stably to some extent.