摘要
洞壁应力恢复法地应力测试具有简易、快速、经济、实用等优点,可应用于斜坡应力场的系统测试和研究。本文采用该方法对某大型水电站枢纽区两岸不同高程勘探平硐洞壁应力场作了较系统测试。测试成果表明,斜坡应力场随深度变化具有明显分带性,斜坡表部应力值较低,随硐深增加,其值逐渐增大,并在某一部位突然增高,出现应力相对集中的现象,而后应力略有降低并逐渐趋于平稳增大。据此,将斜坡浅表部应力场由表及里划分为应力降低带、应力增高带及应力波动带。卸荷带的分布与这一应力分带性密切相关,卸荷带底界往往对应于应力降低带的下限或应力增高带的起始点,划分结果与斜坡岩体结构、变形破裂特征及地震波速具有较好的一致性,表明应力分带性特征可作为斜坡岩体卸荷带综合划分的指标。
The stress restoring method has many advantages, such as simplicity, expeditiousness, economy and practicality, and it can be used to systemically test and study the slope stress field. The method was adopted to test the stress field of the adits with different elevations on both banks of a large hydropower station. The results indicated that the slope stress field had distinct zonation with the variety of depths. The magnitude of stress, a little low on the surface of slop, gradually increased with the depth. And it had a sudden increase at a certain position, where there would be a relative concentration of stress. Whereafter, the stress smoothly increased after a slim lower. Hereby, the stress field on superficial slope could be divided into regions of stress lowering, rising and fluctuating from the outside to the inside. The distribution of unloading zones correlated with the zonation of slope stress, the hemline of unloading zones often corresponded to the floor level of reducing stress region or outset of the rising stress region. The unloading zones were consistent with the rockmass structure, characteristics of distortion and cracking, and seismic wave speed. So, the characteristics of zonation of slope stress field could work as an index to divide the unloading zones of the slope.
出处
《岩土工程学报》
EI
CAS
CSCD
北大核心
2007年第9期1423-1427,共5页
Chinese Journal of Geotechnical Engineering
关键词
应力恢复法
应力测试
斜坡应力分带
应力增高带
卸荷带
restoring stress method
stress testing
zonation of slope stress
rising stress region
unloading zone
