Study On Low Strain Dynamic Response Theory For Bolt-Surrounding Rock System And Its Application

Low strain dynamic response theory is the basis of method in stress wave testing of anchorage system, which can be used to explain the dynamic reaction between anchor bar and surround rock, the mechanics of anchor bar stress wave testing. It is important to establish the approach of defect detecting and to evaluate the anchoring quality of anchorage system.Through theory study, model experiment, numerical simulation, field testing and modern signal process technology, the spread character of different defective anchorage systems and the theoretical model of nondestructive detection are researched. Meanwhile, a quantitative assessment approach of anchoring quality is put forward by artificial intelligence system. The technology of real-time detecting which can meet the requirement of wide scope testing is explored. In this dissertation the main original work includes:(1) The low strain dynamic response model of integrate anchor bar is established, the corresponding analytical solution and semi-analytical solution is developed by using function-transform, generalized function, integral transformation and trigonometric function. The influence of different dynamic parameters is analyzed. The low strain dynamic response model of defective anchor bar under impulse force is established. With Laplace transforms, the analytical expression of transfer matrix or impedance function is derived for the anchorage system subjected to an exciting force at its top. Then a semi-analytical solution of the velocity response in time-domain under semi-sine exciting force is given by using method of Fourier transform. To study on dynamic response with different defects and nondestructive detection of anchorage system, the result provides the theoretical basis.(2) The numerical experiment is done by using finite element analysis. The dynamic responses are simulated for of integrate anchorage system and anchorage systems with different defects through 1-D and axis symmetry numerical calculate. Therefore time domain analysis and modal analysis are done.(3) In dynamic analysis, the variations of dynamic parameters reflect the damaged degree of anchorage system. So dynamic parameters are the vital reference of...