By studying the pile-formula and stress-wave methods (e.g., CASE method), the authors propose a new method for testing piles using the single-impact energy and P-S curves. The vibration and wave figures are recorded,...By studying the pile-formula and stress-wave methods (e.g., CASE method), the authors propose a new method for testing piles using the single-impact energy and P-S curves. The vibration and wave figures are recorded, and the dynamic and static displacements are measured by different transducers near the top of piles when the pile is im- pacted by a heavy hammer or micro-rocket. By observing the transformation coefficient of driving energy (total energy), the consumed energy of wave motion and vibration and so on, the vertical bearing capacity for single pile is measured and calculated. Then, using the vibration wave diagram, the dynamic relation curves between the force (P) and the displacement (S) is calculated and the yield points are determined. Using the static-loading test, the dynamic results are checked and the relative constants of dynamic-static P-S curves are determined. Then the sub- sidence quantity corresponding to the bearing capacity is determined. Moreover, the shaped quality of the pile body can be judged from the formation of P-S curves.展开更多
Considering the level distribution of soil layers, the soils surrounding pile are simulated with level finite layer elements. Supposing that the vertical deformation of the soil elements surrounding pile varies in the...Considering the level distribution of soil layers, the soils surrounding pile are simulated with level finite layer elements. Supposing that the vertical deformation of the soil elements surrounding pile varies in the form of exponent function with radial distance, and considering the nonlinear constitutive relation of stress and strain, the stiffness matrix is established. The mechanics behavior of the pile—soil interface is simulated with a nonlinear interface element. This method can truly express the behavior of the pile-soil system. The load-settlement relation Q-S curves of two big diameter prototype piles on bearing test are analyzed, and satisfying results are obtained. This method is reasonable in theory and feasible in engineering.展开更多
临近桩基受到基坑开挖引起的土体水平位移作用,导致桩身产生附加弯矩、应力和位移,可能降低临近桩基的安全度,这已成为工程界关注的一个重要问题。基于非线性荷载传递的p-y曲线法,采用LPILE Plus 5.0软件对基坑开挖引起的土体位移与临...临近桩基受到基坑开挖引起的土体水平位移作用,导致桩身产生附加弯矩、应力和位移,可能降低临近桩基的安全度,这已成为工程界关注的一个重要问题。基于非线性荷载传递的p-y曲线法,采用LPILE Plus 5.0软件对基坑开挖引起的土体位移与临近桩基的相互作用进行分析,讨论了桩侧土体抗力特性、桩头约束条件和土体位移分布模式等对桩基弯矩、内力和位移等的影响,并根据分析结果,提出一些建议,可供工程设计参考。展开更多
基金Key Projects of Tenth Five-year Plan of Yunnan Province (54-02-02).
文摘By studying the pile-formula and stress-wave methods (e.g., CASE method), the authors propose a new method for testing piles using the single-impact energy and P-S curves. The vibration and wave figures are recorded, and the dynamic and static displacements are measured by different transducers near the top of piles when the pile is im- pacted by a heavy hammer or micro-rocket. By observing the transformation coefficient of driving energy (total energy), the consumed energy of wave motion and vibration and so on, the vertical bearing capacity for single pile is measured and calculated. Then, using the vibration wave diagram, the dynamic relation curves between the force (P) and the displacement (S) is calculated and the yield points are determined. Using the static-loading test, the dynamic results are checked and the relative constants of dynamic-static P-S curves are determined. Then the sub- sidence quantity corresponding to the bearing capacity is determined. Moreover, the shaped quality of the pile body can be judged from the formation of P-S curves.
文摘Considering the level distribution of soil layers, the soils surrounding pile are simulated with level finite layer elements. Supposing that the vertical deformation of the soil elements surrounding pile varies in the form of exponent function with radial distance, and considering the nonlinear constitutive relation of stress and strain, the stiffness matrix is established. The mechanics behavior of the pile—soil interface is simulated with a nonlinear interface element. This method can truly express the behavior of the pile-soil system. The load-settlement relation Q-S curves of two big diameter prototype piles on bearing test are analyzed, and satisfying results are obtained. This method is reasonable in theory and feasible in engineering.
文摘临近桩基受到基坑开挖引起的土体水平位移作用,导致桩身产生附加弯矩、应力和位移,可能降低临近桩基的安全度,这已成为工程界关注的一个重要问题。基于非线性荷载传递的p-y曲线法,采用LPILE Plus 5.0软件对基坑开挖引起的土体位移与临近桩基的相互作用进行分析,讨论了桩侧土体抗力特性、桩头约束条件和土体位移分布模式等对桩基弯矩、内力和位移等的影响,并根据分析结果,提出一些建议,可供工程设计参考。
