不同引渠形式下深式短管进口泄流能力的试验研究

为研究红岩河水库导流泄洪洞深式短管进口引渠形式由明渠改成涵洞后对其泄洪能力的影响,对其在明渠和涵洞两种形式下分别做水工模型试验,验证其水力特性。结果表明,较明渠形式,涵洞形式下的导流泄洪洞同水位下泄流量有不同程度的减小,下泄流量减小在导流泄洪洞进口为压力流状态时表现明显,且减小值随水位的升高而变大;大坝度汛期100年一遇洪水时,试验下泄流量较设计下泄流量约小6.35%;运行期100年一遇洪水时,试验下泄流量较设计下泄流量约小6.51%;运行期2 000年一遇洪水时,试验下泄流量较设计下泄流量约小6.95%。建议在将红岩河水库导流泄洪洞深式短管进口引渠由明渠改成涵洞形式后,需关注导流泄洪洞的下泄流量减小问题,避免由于水库下泄流量不足引起的大坝安全问题。

Experimental Study of Discharge Capacity of Intake with Pressure Short Pipe in Different Forms of Approach Channel

In order to study the effect of the approach channel form of intake changed from open channel into culvert on the discharge capacity of diversion spillway tunnel in Hongyanhe Reservoir, we respectively conducted hydraulic model tests to verify its hydraulic characteristics under the circumstances of two approach channel forms, open tunnel and culvert. The results show:compared with the open channel, the discharge capacity of the diversion spillway tunnel weakens at the same level in the form of culvert, and the phenom-enon is obvious especially when the intake of diversion spillway tunnel is in a state of pressure flow, and the decrease value of discharge will increase with the increase of the reservoir level;the experimental value of discharge is 6. 35% less than the design value when the flood of 100-year frequency (p=1%) occurs during the flood period of dam, 6. 51% less than the design value when p=1% during the operation period of dam, and 6. 95% less than the design value when the flood of 2000-year frequency (p=0. 05%) occurs during the operation period of dam. It is suggested that designers should attach importance to the decrease of discharge to avoid the impact due to the insufficient discharge capacity caused by the approach channel form of diversion spillway tunnel intake changed from open chan-nel into culvert.