New Technologies For Rapid Construction Of Very High Arch Dams And Their Application To Xiluodu Hydropower Project

Technologically, it is very demanding to build ultra-high arches in west Chinawhere the conditions of topography and geology are much more complicated. As theconstruction sites there usually located in high mountains, deep valleys or limited areas,the construction is highly constrained by factors such as topography, geology,hydrology and meteorology. Therefore, the study of key technologies for rapidconstruction of ultra-high dam has theoretical significance and practical implication. Totackle the problem of the11.5months’ delay of dam concrete construction due totreatment of geological defects at foundation base and location adjustment of foundationbase at the early stage, this paper makes a systematic research and analysis on the keytechnologies for the rapid construction of ultra-high dam at Xiluodu HydropowerProject.On the basis of construction conditions and features of Xiluodu arch dam’sconcreting work, and by applying the software “Concreting Simulation System ofDouble Curvature Arch Dam at Xiluodu Hydropower Project”, skip constructionprogram and P3project management software, this paper makes a simulation analysison multi skip construction programs, presents a reasonable optimization program of thegeneral construction schedule, develops the corresponding rapid concrete placementscheme and the supporting construction equipment plan, and analyzes the key factorswhich constrain the rapid construction of the dam and puts forward the correspondingsolutions.On the basis of general program of rapid construction, this paper proposes the onethat suits the rapid construction of Xiluodu arch dam, i.e., highly efficient concreteplacing by using cable machine and its supporting techniques. And by analyzing thesupporting techniques of concreting equipment and concreting site construction it putsforward some corresponding technical measures. Through analyzing key factors thatconstrain the rapid construction of high arch dam and the correspondingcountermeasures, this paper gives detailed analysis on the rapid constructiontechnologies of activities on critical path and in special locations which constrain therapid construction of arch dam, including concrete replacement, consolidation grouting,bottom outlet steel lining and slab concrete, separated construction of bottom outlet gate piers from the main body for rapid concreting, anchorage installed to ultra-long U-shapepier, metal structure fabrication and installation, and arch dam cantilever parts, as wellas provides the corresponding solutions and technical measures. After analyzing theoptimization program of general construction schedule, cooling with water and jointgrouting construction, calculating the strength of cooling with water at different stage ofdam construction and impact of joint grouting to dam cantilever height, this paperprovides reasonable suggestions on appropriate time shortening of water cooling at thelater stage of concrete construction or properly local height increasing of arch damcantilever by simulation calculation and analysis.This paper explains how to achieve the overall management and early warning andforecast for the construction process, safety monitor and research data analysis byadopting construction monitor and simulation system to conduct digitalized monitor andfeedback analysis on the whole process of arch dam construction. It also shows that theapplication of information technologies and the optimization of constructionmanagement model can enhance construction delicacy management and eventuallyprovide strong technical support and guarantee for the qualified and efficient rapidconstruction as well as temperature and crack control of Xiluodu arch dam.The analysis and research results of this paper on the foresaid key technologies forrapid ultra-high arch dam construction have already been applied to the construction ofXiluodu arch dam. At present, the construction progress of Xiluodu arch dam meets therequirements for water impounding and power generation on schedule, which provideseffective technical support for the rapid construction of Xiluodu arch dam.