Detection And Analysis Of Pile Foundation In A Power Plant

With the development of economic and engineering construction in our country,the engineering project with pile foundation continues to increase.Scope of application involves large factory buildings,high-rise buildings,railway and highway bridge,port,wharf,power,offshore platform,water conservancy and other engineering fields.It is particularly effective for pile foundation to reduce building subsidence in soft ground treatment.The pile was buried in underground and it has a high degree of concealment,there are many factors affect the quality.Quality problems directly endanger the normal use and safety of the main structure,However,if the quality problems of pile foundation was produced,it was very difficult to strengthen the treatment.In order to ensure the quality of pile foundation and avoid accident,detection of pile engineering involving the design,construction,inspection,and other links are important.Not only provided a scientific basis for accurate determination and to master the quality of construction engineering pile foundation,but also played a positive role in the true quality of the verification pile,guarantee pile foundation security firm.Firstly this paper described the history of the development process and conditions of use,highlighted the importance of pile foundation quality of building structure security and then leaded to the pile foundation detection technology.After talking about the development history and actuality of technique of pile foundation inspection,the test content classification was introduced,as well as the purpose and the meaning of the pile foundation inspection.The second chapter of the article introduced the static load test sound wave transmission method,borehole coring method,high strain testing,low strain test and several main pile foundation inspection methods,including detection principle analysis method detection process and instrument equipment such as the content,function of various testing methods and suitable scope.The synthetic test method that combined static load test and dynamic test technology was used to test and analysis the designed test piles of pile foundation in a power plant.The test pile including 3 squeezed branch piles,6 branch anchor piles and 20 root piles.The test content included the use of low strain dynamic test method to check all of 29 root piles body quality and defect inspection.The squeezed branch pile and pile static load test determining the vertical and horizontal bearing capacity of piles,included the single pile vertical compressive strength and horizontal static load two events.The strain test of 3 piles through recording measured values under different static load test with stress meter of steel bar to calculate axial force,side frictional resistance and end resistance of pile shaft,and understand the stress distribution of the pile,in order to determine the limit side resistance of soil around the pile and the value of the limit end resistance of the pile.High strain testing use the GOBLE-CAPWAPC-CASE method and PDA pile driving analyzer to collect information.And then adopt PDAWIN CAPWAPC program software for data analysis,calculation and fitting.finally get the exact limit bearing capacity of single pile and compared with the results of the static load method.And judge the application and reliability of the high strain method.By PDA high strain dynamic testing and pile body internal force test,the total resistence of soil around the pile and the end point pile was obtained and analyzed the distribution situation of the resistance around the pile and its end.