摘要
通过福建云霄某水电项目,分析研究早白垩系浯田单元晶洞(钾长)花岗岩,其物理力学特性具有以下特征:密度指标偏低,天然块体密度范围值为2.52~2.59 g/cm3;孔隙率大,饱水系数指标介于0.63~0.98,其抗冻性能较差;新鲜岩石的抗剪断参数偏低,其中黏聚力指标均小于20 MPa;饱和抗压强度指标范围为97.2~250.0 MPa,并未因晶洞发育有明显降低;弹性模量、饱和单轴抗压强度与孔隙率表现出较好的线性相关性,随着孔隙增大,其强度和抗变形特性有一定程度降低;岩石模量比范围为217.5~361.6,属中等模量比岩石,离散性较小,宏观体现为晶洞在岩体内的分布相对均匀。原位岩体钻孔压水试验表明,岩体虽有晶洞发育,但新鲜岩体均以微透水为主,并未表现较强的透水能力,说明晶洞间并未连通,且在8 MPa压力范围内晶洞连通性和结构基本未发生变化。
The cave(k-feldspar)granite has its unique physical and mechanical properties with the growth of rock geode.In this paper,based on a hydropower project in Fujian province,this paper studies the early cretaceous wutian unit cave(k-feldspar)granite,which has the following characters:(ⅰ)low density metrics as the density of natural block ranges from 2.52 g/cm3 to 2.59g/cm3;(ⅱ)large porosity with poor frost resistance,as water saturation coefficient index is between 0.63~0.98;(ⅲ)the shear parameters of the fresh rocks were relatively low,and the cohesion indexes were all less than 20MPa.(ⅳ)The saturated compressive strength ranges from 97.2Mpa to 250.0Mpa,and there is no significant decrease due to the development of crystal cavity.(ⅴ)The elastic modulus has a good linear correlation with the porosity metrics,and are highly discrete,indicating that the development of crystal cavity has a great influence on the deformation resistance of different blocks.(ⅵ)The rock modulus ratio ranges from 217.5 to 361.6,which is classified to the medium modulus ratio rock and has less dispersion,indicating a homogeneous distribution of crystal caves in the rock mass.The borehole pressurized water test of in-situ rock mass shows that although the rock mass has crystal cavern development,the fresh rock mass is mainly slightly permeable and does not show strong permeable ability,indicating that the crystal cavern is not connected.The crystal cavern structure is not changed within the pressure range of 8MPa,and the permeability of rock mass is basically unchanged.
作者
朱事业
ZHU Shiye(Guangdong Hydropower Planning & Design Institute Co.,Ltd, Guangzhou 510635, China)
出处
《广东水利水电》
2021年第2期64-69,共6页
Guangdong Water Resources and Hydropower
关键词
晶洞花岗岩
微(新)岩体
物理力学特性
工程岩体
压水试验
cave granite
micro(new)rock mass
physical and mechanical properties
engineering rock mass
water pressure test
