Research On The Nondestructive Detection Method And Preventing Damage Measures Of RCC Cooling Pipes For Xiangjiaba Dam

In this paper, with the Xiangjiaba RCC concrete cooling water pipe constructionengineering practice, the nondestructive testing technology is proposed and solves theproblem of damage of the cooling pipe and the key technical issues of RCC coolingwater pipeline construction is researched, the following innovations are obtained.1. The research for the risk of pre-judgment and analysis for RCC cooling pipesdisplacement and damage.Through analysis thorough of the RCC site constructionenvironment, the risk of pre-judgment for RCC cooling pipes displacement anddamage is completed，combining with a amount of stress analysis calculations，theanticipation of the level of risk is completed.2. The research for the comparison and practice of cooling pipes nondestructivedetection technology and space positioning technology is completed.By comparingthe performance of the the pipeline meter and geological radar instrument and thecomparison of the three options for the pipeline Miriam+wire, pipeline Miriam+water and direct detection of geological radar, the feasibility of detection scheme forpipeline Miriam+wire is determined. By the comparison and selection of variouspositioning methods, the positioning method of the baseline+handheld infraredrangefinder is determined. The feasibility and application prospects of high-precisionGPS approach are explored.3. The engineering measures for positioning of cooling water pipe laying andpreventing damage is verified.Combining with RCC construction of the left bankSegment forXiangjia-ba hydropower station, the soaring two-layer concrete positionswithin a7-layer cooling water pipes is tracked detection. The targeted responsemeasures are developed to prevent the shift and damage of the RCC cooling pipes,which is verified through field experiments. The two outcomes of the mainanti-displacement measures is obtained, Firstily, combining with RCC deck featuresand cutting order, the cooling water pipe layout principles and control measuresduring construction is determined. Secondly, the process improvements for pipesfixed tools and reinforcement after the cooling water is layed.4. The comprehensive utilization of cooling pipes precise spatial locationinformation is explored. By nondestructive detection, precise positioning andinformation collection technology, the digitized data of cooling pipes is established a three-dimensional visualization model and achieving converting text-based date to athree-dimensional model.,On this basis of which, the grouting three dimensionalmodel is coupled to the cooling water pipe model, to achieve a seamless connection.Through the coupling model, it is possible to clear the relationship between thecooling water pipes and grouting, and then judged whether the grouting hole and thecooling water pipes intersect and the spatial position. The visual warning forconstruction of the pore-forming and a precise basis is provided to cooling waterpipese to avoid making holes.5. Nondestructive detection method and the simulation of temperature stressbased on precise spatial location of the cooling water pipe for RCC, and the value ofpreventing damage measures in normal concrete arch dam project are exploded.