Fengman Concrete Gravity Dam Anti-seepage Treatment And Osmotic Pressure Reduction Grouting Technology And Result Research

There are many different seepage characteristics between concrete dams in thecold areas with them in other areas. As Northeastern China, it annually starts to freezegenerally in late October and to melt gradually in next April. The whole frozen periodeven lasts about5-6months. During the frozen period, seepage dam, diversion holeand other structures were blocking uncompacted, rise and fall of water level,precipitation of early winter, etc. made concrete saturated. With reversed cyclic actionof temperature above or below zero, dam concrete surface had freeze-thaw damageand inner frost heaving damage.Engineers at home and abroad had done a lot of work about seepage of concretedam study. According to seepage causes and the aim of anti-seepage treatment, tochoose appropriate engineering measures (mostly by grouting) or grouting material, inorder to meet the safety requirements of projects. After anti-seepage treatment,concrete dam’s stability of the global structure and change of cracks’local mechanicalstate must rely on grouting material characteristics, technology of grouting and localmechanics of cracks to guide grouting construction. This is an actual problem in manyhydropower projects.This thesis main research content:1. To analyze grouting result, combining with Fengman anti-seepage treatmentand osmotic pressure reduction project, this thesis presents technological parametersof aged concrete dams grouting construction in the cold areas, such as groutingmaterial, water cement ratio, grouting pressure, etc.2. With grouting construction technology, quality control, core sample test ofmechanical properties, acoustic CT test, the method of bore hole television,underwater television observation, Deformation Monitoring in front of dam,numerical changes of drain holes’ uplift pressure and the wetting line, etc., this thesisevaluated grouting result comprehensively and summarized a set of method ofgrouting technology and grouting result test for the seepage of aged concrete dams inthe cold areas. This thesis summarized a set of standards of aged concrete damsgrouting construction in the cold areas.3. With calculation of three dimensional nonlinear finite element simulationbefore and after grouting, this thesis analyzed differences of the stability of the globalstructure and important part and local mechanical properties of cracks of concrete dams after grouting. According to the relevance between the stability and the stressstate of dams after grouting and grouting material, technology and environment, byadjusting grouting material, method and environment, to determine appropriategrouting technology.This thesis aimed at seepage reasons of concrete sick dams in the cold areas, toadopt appropriate anti-seepage treatment (grouting) and construction technology, toevaluate anti-seepage result comprehensively, to summarize the regularity ofanti-seepage treatment, to provide guidance for anti-seepage treatment of agedconcrete dams in the cold areas.