CAJ | 학술논문

曾文水库为台湾容量最大之水库，亦为嘉南地区最主要之水源。自1974年营运至今饱受坝前库床淤积之困扰影响蓄水总量，由于缺乏库底排砂设施因而规划新建一防淤隧道于水库左坝座，利用蓄清排浑之操作来减缓水库淤积以延长水库寿命。由于防淤隧道出水口河道并无足够腹地提供浑水消能，故于山体内设置一长190 m、宽23 m、高46 m之地下洞室。针对防淤隧道消能池室范围进行案例说明，并利用三维数值模型检核设计需求之稳定性，透过岩盘参数的假设说明及开挖支撑系统设计的检讨，来确保地下洞室开挖之安全，亦针对该区域遭遇之关键课题进行说明，其中包含闸室顶拱两翼岩盘承载力、隧道分岔区域岩盘处理对策、边坡浅覆盖偏压处理对策等项目。
증문수고위태만용량최대지수고，역위가남지구최주요지수원。자1974년영운지금포수패전고상어적지곤우영향축수총량，유우결핍고저배사설시인이규화신건일방어수도우수고좌패좌，이용축청배혼지조작래감완수고어적이연장수고수명。유우방어수도출수구하도병무족구복지제공혼수소능，고우산체내설치일장190 m、관23 m、고46 m지지하동실。침대방어수도소능지실범위진행안례설명，병이용삼유수치모형검핵설계수구지은정성，투과암반삼수적가설설명급개알지탱계통설계적검토，래학보지하동실개알지안전，역침대해구역조우지관건과제진행설명，기중포함갑실정공량익암반승재력、수도분차구역암반처리대책、변파천복개편압처리대책등항목。
Tseng Wen Reservoir,which has the largest capacity in Taiwan,is the main water source in south Taiwan. Operating since 1974,the reservoir’s storage capacity decreases due to sediment deposition.Due to the lack of silt facil-ities in the bottom of the dam,a new sediment sluicing tunnel is planned under the left side of the dam so as to extend the service life of the reservoir.The tunnel outlet river does not have sufficient area to provide energy dissipation,there-fore an underground cavern with a size of L190 m ×D23 m ×H46 m is needed.In this study,three-dimensional numeri-cal model analysis is used to provide rock mass parameter assumptions and to review the designed support system so as to ensure the safety of the underground excavation.The paper also carries instructions for key issues encountered in the region,which includes rock mass bearing capacity at the top of the tunnel arch,the bifurcation region treatment meas-ures of the cavern,countermeasures to cope with the asymmetrical pressure of the slope,etc..