Font Size: a A A

Probability Evaluation Of Cataclastic Rock Mass Used For High Concrete Dam Foundation

Posted on:2006-05-19Degree:DoctorType:Dissertation
Country:ChinaCandidate:Y X CuiFull Text:PDF
GTID:1102360155458554Subject:Geological Engineering
Abstract/Summary:PDF Full Text Request
Basalts with chloritized joints were distributed in dam foundation and two banks of low altitude in Jin'anqiao hydroelectric station, and these special basalts were named basalts with chloritized joints. Basalts were cutting severely by dense chloritized joints. In the light of current code for water resources and hydropower engineering geological investigation(GB50287-99), types of rock mass structure should be inlaid cataclastic structure or cataclastic structure, and types of rock mass quality should be grade IV or grade IQ2, but in situ condition, basalts closely locked. Could these special rock masses been used as foundation of high concrete gravity dam? The study of basalts with chloritized joints had theoretical and engineering significance. So taking Jin'anQiao hydroelectric station on Jinsha River as an example, some problems closely related to the stability of rock mass surrounding dam foundation were analyzed in detail from the engineering geologic points of view. And the main contents of this dissertation were:(1) Through field investigation and analysis, found out developmental characteristics of basalts with chloritized joints: chlorites mainly developed in basalt columnar joints; chlorites having some cementing action for two sides basalts; chloritized joints with steep angle of dips; chloritized joints with short traces.(2)According to field and indoor investigations and tests, genetic mechanism of chloritized joints were analyzed in detail. The formation of chlorites in basalt joints had two modes: first mode was hydrothermal alteration after formation of basalts, second mode was that chlorites in thermal fluid had deposited on two walls of joints.(3)Using indexes of Code of GB50287-99 to appraise the rock mass structure types of the basalts with chloritized joints, results had distinct disagreements. So the basalts with chloritized joints of Jin'anqiao hydroelectric station dam foundation were new special cataclastic structure rock masses. These cataclastic structure rock masses were discreted in situ, and differentiated with fracture zone by tectonic process or displacement. In this dissertation, these new special structure rock masses were named inlaid cataclastic structure rock mass in situ. The inlaid cataclastic structure rock mass in situ had some characteristics: with quasi-integrality; low permeability, high rock mass wave velocity, high deformation modulus. Based on these characteristics, put forward the rock mass structure classification scheme of these new inlaid cataclastic rock mass in situ.(4)According to field and indoor investigations and tests, under the conditions of in situ or slight disturbance, basalts with chloritized joints had high intensive and deformation parameters. Results of indoor basalt fragments high-pressure test(maximum pressure:750MPa) proved that the inlaid cataclastic rock mass in situ of Jin'anqiao hydroelectric station dam foundation had high deformation modulus (more...
Keywords/Search Tags:inlaid cataclastic rock mass in situ, basalt, rock mass with chloritized joints, rock mass structure, rock mass quality, rock mass mechanical parameters, dam foundation rock selection, dam foundation deformation, dam foundation stability against sliding
PDF Full Text Request
Related items