Research On Integrity Detection Technique For Highway Pile Foundation In Jilin Province

With the rapid development of China’s national economy and the advancementof urbanization, demands on infrastructure of modern society has increasedgradually. Because of its advanced technology and component complexity for bridgeengineering, its security operations for the protection of the entire transportationlines is of great significance. As an important part of the bridge substructure, pilefoundation can provide for the carrying capacity for the upper structure. However,the type of foundation construction process is relatively complex and excellentconstruction workers are less, which causes many flaws of piles such as isolation,bottom sediment and so on. Considering pile integrity is guaranteed a highercarrying capacity sufficient condition, it is important to effectively detect itsconstruction quality, timely detection of construction defects and take necessaryremedial measures for ensuring the safe operation of engineering structures. In thispaper, the construction of highways in Jilin Province is constructed using low strainreflected wave method, ultrasonic method and coring method for pile integrityevaluation, specific work are as follows:(1) Commonly used method of pile integrity testing concepts, testingprocedures and precautions were elaborated, the advantages and disadvantages ofthe method are analyzed and related technology research status is discussed.(2) The theory of ultrasonic wave reflection method and low strain pileintegrity testing are elaborated, including acoustic and vibration, acousticpropagation velocity, reflection and transmission and pile vertical vibration waveequation, piles transient vibration response characteristics. It can providetheoretical basis for the actual construction of pile integrity testing.(3) The parameter settings, trailer coupling pretreatment, sensor mounting andintegrity assessment techniques for low strain reflected wave method are describedin detail. Testing basic parameters and time domain reflection curve are analyzed, calculated and evaluated combined with Jilin-Caoshi Expressway and YingFuExpressway. Test data analysis of low strain reflection wave method is described indetailed.(4) The field testing technique for untrosonic method of pile foundationevaluation is discussed comprehensively. Wave velocity, amplitude and PSDparamater are described. Combining with actual project, the typical wave cures forpiles are disscussed. The comprehensive survey of ultrosonic method, low strainmothod and coring method is applied in filed tests.（5）A new comprehensive assessment method of pile construction qualitybased on uncertain analytic hierarchy process is proposed. This method establishesthe comprehensive assessment index system of pile construction quality. Itconstructs pile construction quality assessment model through determining theweight of each index based on analytic hierarchy process to improve the evaluationmethod of pile construction quality. The good results achieved in practicalengineering demonstrate that the proposed method possesses favorable accuracy.