天堂山水库拱坝初期蓄水监测成果

天堂山拱坝是一座坝高约７０米的双曲拱坝，为保证大坝安全蓄水，利用埋设在坝内的仪器观测系统和布置于坝基廊道的排水－扬压孔系统，选择部分控制蓄水安全的重点监测项目，进行了蓄水安全监控，初期蓄水监测结果表明：１、拱坝坝体温度变化规律，分布合理，其状态对大坝的应力和整体性有利；２、大坝的内部应力变化符合一般规律，量律、分布合理，变化均匀，出现的最大拉压应力符合现行规范；３、接缝灌浆质量良好，横缝未出现重被

Monitoring results of Tiantangshan arch dam during early stage of impoundment

Tiantangshan arch dam is of double-curvature with a height of about 70m. In order to ensure its safety in impounding the reservoir,some important monitoring systems and items have been selected. They consist of the observation system embedded in the dam and the drainage-uplift holes system arranged in a gallery in the dam foundation. The monitored results in early stage of impoundment show:(1)The temperature variation and the temperature distribution are reasonable,and the temperatrue state is favorable to the stresses and the integrity of the dam;(2)The stress variation in the dam conforms to the general law The values of stresses and their distribution are reasonable and with a uniform variation the maximum tensile and compressive stresses occurring in the dam coinside with the present norm;(3)The quality of joint grouting is good and the transverse joints have not been re opened;(4)The horizontal work joints and the contact joints between the dam foundation and rock are well bound,and values of seepage pressures in the dam body are reasonable with their variation being normal and transverse attenuation being more rapid;(5)Observed values of uplifts in the dam foundation are generally less than the permissible designed values,and the seepage discharge is very small.According to the observed data and the investigated results in site,it.can be concluded that in the early stage of impoundment,the operational behaviours of the dam are normal,and the strength and stability of the dam can satisfy the requirements for raising the reservoir water level.