Research On Foundation Pile Checking By Analysis And Comparison On Ultrasonic Transmission Method And Reflected Wave Method

With the rapid development of construction projects in China, as a kind of veryimportant foundation forms, pile foundation are widely used in the basic engineering such asbridges, high-rise buildings, heavy factories, port and offshore oil platforms.In various typesof pile foundation, concrete pouring pile is most widely used, particularly in large diameterpile foundation basically all use of bored concrete pile.However, due to the foundation pilesare hidden works, the construction procedure is difficult, demanding, and susceptible to theinfluence of geological conditions, construction techniques, working conditions, personaloperation and other factors, leaving the concrete grouting pile quality. The basis of quality isthe fundamental quality of the project, related to people’s life and property safety. For pile, theintegrity test is more meaningful than the bearing capacity of detection. Therefore, whetherthe appropriate choose detection methods, detecting pile integrity accurately and rapidly isparticularly important.Starting from the basic principles and methods of the ultrasonic transmission methodwith low strain reflection wave method, tell the basic theory, equipment and detectiontechnology of the two methods, elaborate relationship between the concrete acousticparameters such as wave velocity, amplitude, frequency, PSD and the defect types, as well asthe relationship between the time curve and the type of pile defects. Using the finite elementmethod to simulate the low-strain testing process, to study the relationship between thereflection time and their impact parameters to come up with some regularity.With anengineering example, using two detection methods to detect, in terms of detection range, blindspot of detection, sensitivity and reliability, as well as bottlenecks in the development, throughcomparative analysis of experimental data and test results, make clear the advantages andinadequacies of two detection methods. For security reasons, pile integrity detection shouldadopt the joint detection of the ultrasonic transmission method with low strain reflected wave,so that strengths can be effective to avoid undetected, error detection, to improve the accuracyand reliability of the pile foundation inspection.