土木土建68说明书A江坝后式厂房双曲拱坝设计

摘要

A江是我国东南地区的一条河流，根据流域规划拟建一座水电站。

A江水利枢纽同时兼有防洪、发电、灌溉、渔业等综合作用，水库正常蓄水位183.75m，设计洪水位186.7m，校核洪水位189.80m，汛前限制水位182m，死水位164m，尾水位103.5m。水库死库容 4.76亿m3，总库容9.6亿m3。

A江水利枢纽工程等别为一等，工程规模为大（1）型工程，主要建筑物级别为1级，次要建筑物级别为3级，临时性建筑物级别为4级。

A江水利枢纽的主要组成建筑物有挡水建筑物、主副厂房、泄水建筑物、过木筏道等。

经过坝型比选，选定挡水建筑物为一变圆心变外半径的双曲拱坝，坝顶弦长312m，最大坝高100.4m，坝底厚25.7m，坝顶宽8.5m。

设计中对四种工况的坝体应力分别采用了电算和手算，手算运用拱冠梁法。

泄水建筑物由两个浅孔和两个中孔组成：浅孔位于两岸，孔口宽8.5m，高8.0m，进口底高程为164m，出口底高程为154m；中孔位于水电站进水口两侧，孔口宽7.5m，高7.5m，进口底高程为135m，出口底高程为130m。在坝身泄水孔的上下游侧分别布置检修闸门和工作闸门，检修闸门采用平板门，工作闸门采用弧形闸门，在每一个工作闸门的上方有启闭机房，浅孔启闭机房高程为173.38m，中孔启闭机房高程为150.82m。泄槽支撑结构采用框架式结构。坎顶高程为117.m,浅孔反弧半径为40m,中孔反弧半径为50m。泄槽直线段的坡度与孔身底部坡度一致,挑射角θ=20o,导墙厚度为1.0m, 浅孔导墙高度为8.5m,中孔导墙高度为11m。

坝后式厂房装有4台5万kW的发电机组，主厂房长81m，宽18m，副厂房长66m，宽10m，安装场长21m，宽18m。压力管道的直径为4.6m，进水口底高程为152.4m。发电机层高程为114.8m，尾水管底高程为90.8m，厂房顶高程为130.5m。

为防止坝基渗漏，在坝基靠近上游侧进行帷幕灌浆，并且为了减少坝基的扬压力，在灌浆帷幕之后设置排水孔。各孔间距均为5.0m。

为了防止混凝土产生裂缝，拱坝坝体设置横缝，横缝面上需设置键槽，以咬合加固，增强坝体的抗剪能力。当底宽在40～50m以上的拱坝，才考虑设置纵横缝，而本设计中，拱坝坝底宽为25.7m，小于40m，故可不设置纵缝。

Abstract

A jiang is a river which lies in southeast of China.According to drainage area programming,a water power station is planning to built on it . A jiang hydrocomplex plays an important parts in flood control ,waterpower, irrigation, fishery and so on.

The reservoir normal water level is 183.75m,design flood level is 186.7m,maximum flood level is 189.80m,flood control level is 182m,dead water level is 164m, tailwater level of hydropower station is 103.5m.The dead reservoir capacity is 476,000,000m3,and the total reservoir capacity is 960,000,000 m3.

The hydraulic engineering grade is Grade I. The key 、secondary and temporary structures’ grade is Grade I、III and IV.

The key hydroproject is consist of water retaining structure,power house,auxiliary room,sluice structure,raft sluice,and so on.

The water retaining structure is a double curvature arch dam.The length of the axis of crest dam is about 312m.Maximum height of the dam is 100.4m,the thickness of the bottom of the dam is 25.7m,and the width of the top of the dam is 8.5m.

In this design, we use two different methods to calculate the stess of the arch dam in four status.One is using program ,the other is using crown cantilever method to calculate.

The release structure is comprised of 2 mid-level outlet and 2 short-level outlet.The width of the short-level outlet is 8.5m,and the height is 8.0m;the width of the mid-level outlet is 7.5m,and the height is 7.5m.The upstream and the downstream side of every outlet are a bulkhead gate and a operating gate which is a radial gate.There is a room where a gate hoist is put above every service gate.The two rooms which are above the mid-level outlet service gate are at an elevation of 150.82 metres,and the other two rooms are at an elevation of 173.38 metres.The intake of the mid-level outlet is at an elevation of 135 metres,and the intake of the short-level outlet is at an elevation of 164 metres.

The power house lies at the damtoe.The dimensions of the power house and the auxiliary room are 81m×18m and 66m×10m.The generator floor is at an elevation of 114.8m metres,and the bottom of the draft tube is at an elevation of