【摘要】：在建總裝機量第一的金沙江白鶴灘水電站,開挖揭露出大量柱狀節(jié)理玄武巖。因柱狀節(jié)理玄武巖結構的特殊性,有必要對卸荷柱狀節(jié)理玄武巖也即柱狀節(jié)理玄武巖卸荷層的力學特性展開深入的研究。本文通過資料搜集、現(xiàn)場試驗及聲波測試等手段,在壩址區(qū)柱狀節(jié)理玄武巖卸荷松弛特征的基礎上,對卸荷柱狀節(jié)理玄武巖的變形和強度特性展開了研究,論文主要工作內容如下:1、華東院長期對柱狀節(jié)理玄武巖平硐及坡面巖體聲波測試結果表明卸荷松弛具有時效性、尺寸效應:小尺寸時,隨著尺寸的增大,松弛深度增大,較大尺寸時,松弛深度不再增大;柱狀節(jié)理玄武巖松弛深度基本在0.6~2.9m左右;錯動帶對巖體松弛有一定的影響。2、變形特性:剛性承壓板試驗結果顯示白鶴灘卸荷柱狀節(jié)理玄武巖變形模量具有明顯的各向異性,且與應力水平和圍壓相關。三軸變形試驗結果同樣表明:卸荷柱狀節(jié)理玄武巖變形模量的各向異性受圍壓水平的影響;正壓力水平對變形模量的影響體現(xiàn)為應力與應變關系非線性;卸荷回彈變形曲線具有顯著非線性。3、強度特性:通過現(xiàn)場三軸試驗,得到白鶴灘卸荷柱狀節(jié)理玄武巖的MohrColumb及Hoek-Brown強度模型參數(shù)。
[Abstract]:A large number of columnar joint basalts are exposed by excavation of Baihetan Hydropower Station in Jinsha River, which has the highest total installed capacity. Because of the particularity of columnar joint basalt structure, it is necessary to deeply study the mechanical properties of unloading columnar joint basalt. In this paper, the deformation and strength characteristics of columnar joint basalt are studied by means of data collection, field test and acoustic wave test, based on the unloading relaxation characteristics of columnar joint basalt in the dam site. The main work of this paper is as follows: 1. The results of acoustic wave test of columnar joint basalt adit and slope rock mass show that unloading relaxation has time-effect and size effect: when the size is small, the relaxation depth increases with the increase of size. When the size is larger, the relaxation depth will not increase. The relaxation depth of columnar joint basalt is about 0.6 ~ 2.9 m; (2) deformation characteristics: the test results of rigid bearing plate show that the deformation modulus of Baishetan unloaded columnar joint basalt has obvious anisotropy and is related to stress level and confining pressure. The results of triaxial deformation test also show that the anisotropy of deformation modulus of unloaded columnar joint basalt is affected by confining pressure level, the influence of positive pressure level on deformation modulus is nonlinear between stress and strain. The unloading springback deformation curve is significantly nonlinear. 3. Strength characteristics: through field triaxial tests, the MohrColumb and Hoek-Brown strength model parameters of the unloading columnar joint basalt in Baihetan are obtained.
【學位授予單位】：長江科學院
【學位級別】：碩士
【學位授予年份】：2016
【分類號】：TV223
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本文編號：2305242