水电能源科学

广东惠州中洞抽水蓄能电站高压岔管运行期最大水头约800 m,其高内水压下的围岩稳定性对电站安全运行至关重要。为此，开展现场地应力与高压压水试验，联合三维地应力场反演，分析了高压岔管部位的地应力场分布规律、渗透特性及抗劈裂能力，并优化岔管布置。结果表明，高压岔管段最大主应力为15.0～16.6 MPa,最小主应力为8.4～9.7 MPa;岩体渗透率介于0.01～0.19 Lu之间，呈极微—微透水；初设岔管位置满足抗抬和抗渗透要求，但岔管口7 m范围内Ⅲ类岩体洞段受断层影响，不满足工程抗水力劈裂要求；通过围岩条件和抗抬、抗劈裂及抗渗透等因素综合分析，将初设岔管位置向厂房方向平移10 m,平移后可满足抗抬、抗水力劈裂和抗渗透稳定要求。

The maximum water head endured by the floor of the high-pressure branch pipe at the Zhongdong Pumped Storage Power Station in Huizhou, Guangdong, is approximately 800 m during operation. The stability of the surrounding rock under this high internal water pressure is critical to the station's safe operation. To address this, in-situ stress and high-pressure water injection tests were conducted. Combined with three-dimensional in-situ stress field inversion, the stress field distribution, permeability characteristics, and hydraulic fracturing resistance of the high-pressure branch pipe area were analyzed, and the layout of bifurcated pipe was optimized. The results indicate that the maximum principal stress in the high-pressure branch pipe section ranges from 15.0 to 16.6 MPa, and the minimum principal stress ranges from 8.4 to 9.7 MPa. The rock permeability ranges from 0.01 to 0.19 Lu, indicating very low to low permeability. The initial high-pressure branch pipe location meets the stability requirements against uplift and seepage. However, within a 7 m range of the branch pipe opening, the class Ⅲ rock mass segment is affected by faults and does not meet the engineering requirements for hydraulic fracturing resistance. Based on a comprehensive analysis of the surrounding rock conditions, uplift resistance, hydraulic fracturing resistance, and seepage resistance, the initial high-pressure branch pipe location was shifted 10 m toward the powerhouse, which meets the stability requirements for uplift, hydraulic fracturing resistance, and seepage resistance.