基桩施工（Foundation pile construction）.docVIP

基桩施工（Foundation pile construction） Karst cave pretreatment scheme Overview of the 1 program The peripheral grouting method is adopted to increase the location of cavern and the strength of hole wall. The grouting hole is made of three layers of casing The method is followed by the use of a 146mm sleeve at the outermost layer. The platform is inserted into the seabed sludge The root stability of the casing is the principle. The middle casing is followed by a 127mm to the rock layer, and the depth of the rock is 30 ~ 50cm. The innermost casing is drilled into the bottom of the cave at 1.0m depth by 91mm. After drilling, the drilling slag is removed from the casing and inserted into the jet pipe to spray the high-pressure cement slurry. 2 main machinery and equipment The main equipment and equipment for the pretreatment of pile foundation karst cave are shown in the following table. Table 2-1 table of main machines and tools Serial number name specification quantity remark 1 generator 300KW 6 2 rig 150KW 12 geological drill 3 crawler crane 50t 2 object machine transfer 4 mixing ship - 1 5 high pressure grouting machine - 2 6 freighters - 1 3 Efficacy Analysis The pretreatment time mainly concentrates in the drilling construction process, and the single hole forming time is 1 days, each pile foundation cloth 3 drilling machines are installed, and the treatment time is 5 days for cave height 3.0m ~ 5.0m. The cave height is greater than 5.0m in the karst cave The time is 10 days. 4 construction preparation The site preparation: arrange the track in the casing, in accordance with the design of grouting hole cutting platform panel for drilling rig Placement provides better working surfaces. The raw materials and raw material inspection qualified rear can use. The mix design: before the construction of the double liquid mixture ratio design, cement water cement ratio in the range of W/C 0.8:1 ~ 1:1, water glass: cement slurry (volume ratio) range from 5% to 20%. The slurry m