丰宁抽水蓄能电站地下厂房岩锚梁不均匀沉降规律分析

Analysis of Uneven Settlement Law of Rock Anchor Beam in Underground Powerhouse of Fengning Pumped Storage Power Station

在抽水蓄能电站地下厂房施工中,岩锚梁易出现不均匀沉降导致厂房结构不稳定。本文依托丰宁抽水蓄能电站地下厂房岩锚梁施工现场,对一、二期厂房岩锚梁14个监测断面的边墙进行应变和沉降分析,得出各监测点的应变变化趋势和岩锚梁相对沉降量变化范围,分析结果表明:①一期厂房Ⅰ-Ⅰ断面与Ⅱ-Ⅱ断面、Ⅲ-Ⅲ断面岩锚梁监测点虽然都有波动,但各监测断面相对沉降量在2020年6月都出现平稳,说明一期厂房岩锚梁沉降较稳定;②二期厂房最大相对沉降量为0.13mm,随时间推移其相对沉降量变化范围基本保持不变,并未出现较大沉降,说明二期厂房岩锚梁沉降较为平稳;③岩锚梁发生不均匀沉降的原因与施工、运行工作阶段等多方面均存在联系,因此要保证岩锚梁的正常运行,对岩锚梁的施工、运行和后期支护要进行全方位考虑。

In the construction of underground powerhouse of pumped storage power station,uneven settlement of rock anchor beam is prone to cause instability of powerhouse structure.Based on the construction site of rock anchor beam in underground powerhouse of Fengning Pumped Storage Power Station,this paper analyzes the strain and settlement of the side walls of 14 monitoring sections of rock anchor beam in Phase I and Phase II powerhouses,and obtains the strain variation trend of each monitoring point and the variation range of relative settlement of rock anchor beam.The analysis results show that:①Although the monitoring points of rock anchor beam in Phase I powerhouse Ⅰ-Ⅰ section,Ⅱ-Ⅱ section and Ⅲ-Ⅲ section have fluctuations,the relative settlement of each monitoring section is stable in June 2020,indicating that the settlement of rock anchor beam in Phase I powerhouse is relatively stable.②The maximum relative settlement of the second-stage powerhouse is 0.13 mm,but the variation range of the relative settlement remains basically unchanged over time,and there is no large settlement,indicating that the rock anchor beam settlement of the second-stage powerhouse is relatively stable;③The cause of uneven settlement of rock anchor beam is related to many aspects such as construction and operation stage.Therefore,it is necessary to ensure the normal operation of rock anchor beam and the construction of rock anchor beam.Full consideration of operation and later support.