Ash Dam Radiation Well Drainage System Construction Technology And Mechanical Performance

The seepage and drainage system of ash-shield embankment radiating well is a creative technology which is adopted to strengthen the dam and guarantee the stability of the dam body for retaining ash by decreasing the water level of the ash yard. After a survey on the relevant research results at home and abroad, and taking the seepage and drainage system of ash-shield embankment radiating well in Leiyang Power Station as the project background, this paper intends to analyze the pressure situation on radiating well and pipe-jacking by employing appropriate calculation method and finite element numerical modeling, and do research on the vital construction technologies, such as the settlement of such a radiating well, the pipe laying of the diversion steel tubes and the pipes. The main jobs and conclusion include:1. Through the combination of drilling technology, chemical constituents analysis, soil tests and field test, chemical constituents, physical and mechanical properties, hydrolytic property of the fly ash accumulation Horizon caused by wet discharging technique were analyzed in .detail. As a result, the physical property, Compression Properties, hydrolytic property, strength index and ground bearing capacity were confirmed.2. For the physical and mechanical properties of the cumulating fly ash layer, suitable radiating well construction technology was carefully studied on. Necessary mechanical calculation and construction technology research were carried out under the operation conditions of the construction, settlement, bottom sealing of the radiating well.3.The causes of "ash stream" in this project were dug out. Respective engineering measures for partial and general "ash stream" were formulated to ensure the project could go on smoothly.4. The researches on the pipe laying of the diversion steel tubes by non-tunnel method and other vital construction technologies were made, and subsequently effective measures were put forward. These vital construction technologies include:â‘ resistance-decreasing technology;â‘¡the technology of heading direction control without the help of the direction indicator and rectification bits;â‘¢the connection technology of the diversion steel tubes among wells;â‘£the drilling technology to harness "ash stream"5.The construction technology of laying ABS radiating well pipes in cumulating fly ash layer according to the non-tunnel method.6.According to the calculated result and the reality of my enterprise, a twin-plunger push bench pipe mill was excogitated and the treatment toward the joints of the steel jacket was improved, assisting with small tonnage horizontal drilling machines, thus the difficulty in horizontal equipment of radiating well pipes and the diversion steel tubes in narrow vertical wells was managed to be settled.7.Adopted the methods of numeral simulation calculation and practical calculation, the displacement, internal force of the radiating well earth pressure on the well during the jacking pipe pushed forward were carefully analyzed.