斯里兰卡莱拉多拉电站项目设计说明-译稿-COACH-20110917教材.docVIP

(Lenadora Power Station Project in Sri Lanka) Design Description of Pressure Forebay, Pressure Pipeline and Power Plant at Power Station I. Pressure Forebay 1. Overview Due to the site constraints of key national heritage conservation area, the forebay of power station is in the long and narrow shape, and located at the end of diversion channel with the stake No. from 0++346.8 to 0+389.072, total length of 42.272m, inlet width of 14m, end width of 18.508m, net length of 35m and inlet’s net width of 12m. Stake No. gradually changes to 16.508m from 0+362.8m, and the transition section is 10m long. The elevation of bottom board of forebay (end of diversion channel) is up to 96.895m, and decreases to 94.395m through a 15m slope (1:6). The total accumulation is 2216m3, including the effective capacity (intake chamber roof of 96.695m to the normal water level) of 1433m3. The normal water elevation of forebay is 99.895m. According to the introduction of owner, the forebay has no draining site, and the draining port is located at the diversion channel in front of forebay inlet. Based on the reference flow of Q=23m3/s, if the water depth h is equal to 0.5m, the width of draining port is greater than 32m, so the elevation of forebay top is 101.0m. The owner shall try to set the draining port at the end of diversion channel. 2. Structure ① Sidewall: the sidewall is poured with the C20 reinforced concrete, with the bottom width of 2.042m and top width of 1.0m. The gradient of 97.175m ~ 100m inner slope is 1:0.3, and the rest is straight wall, with the maximum wall height of 7.505m and top elevation of 101.0m. ② Bottom board: the bottom board is a 0.1m C15 concrete cushion, with the upper part of 0.8m C20 reinforced concrete. ③ Three expansion joints are set on the forebay bottom and sidewalls (at a vertical interval of 10m). The expansion joint is sealed with the 300*10mm flat rubber, and the seam is filled up with the tarred fir board and tarred hemp rope. II. Pressure Pipelin