Based on Mindlin stress solution, a numerical computational method was proposed to calculate the stresses in the ground induced by side friction and the resistance of Y-shaped vibro-pile. The improved Terzaghi's a...Based on Mindlin stress solution, a numerical computational method was proposed to calculate the stresses in the ground induced by side friction and the resistance of Y-shaped vibro-pile. The improved Terzaghi's and ЪерезанцевВГ's methods for ultimate bearing capacity evaluation were proposed by considering the stress strength induced by friction resistance at pile head level of Y-pile. A new method to calculate the ultimate bearing capacity of Y-pile was also proposed based on the assumptions of soil failure mode at the tip of Y-pile and the use of Mohr-Coulomb soil yield criterion and Vesic compressive correction coefficient with the induced stresses in the ground. Based on the comparisons with the field static load test results, it is found that the improved Terzaghi's method gives higher ultimate capacity, while the other two methods shows good agreement with the field results.展开更多
The buoyancy of groundwater can reduce the foundation bearing capa-city and cause the metro tunnels to float as a whole,which threatens the safety of structures seriously.Therefore,uplift piles are set up to improve t...The buoyancy of groundwater can reduce the foundation bearing capa-city and cause the metro tunnels to float as a whole,which threatens the safety of structures seriously.Therefore,uplift piles are set up to improve the structural sta-bility.In this paper,FLAC3D software is used to establish the calculation models of pile foundation.The bearing failure process of uplift piles was simulated to study the influencing factors on single pile load bearing capacity as well as the cooperative work laws of pile groups.The load-displacement curves of pile top under different length-diameter ratios,pile soil interface characteristics and pile types are obtained,respectively.The results showed that,increasing the length-diameter ratio and the pile-soil interface roughness properdly can improve the bear-ing capacity of uplift piles.Besides,changing the shapes of constant pile section can also improve it,which has the most significant effect concerning of saving material cost.In the loading process of pile groups,the ultimate bearing capacity of corner pile is the biggest,the side pile is the next,and the center pile is the smallest.The de formation characteristics of pile top are as follows:the center pile is the biggest,the side pile is the next,and comer pile is the smallest.Combined with the results,the uplift resistance of group piles can be enhanced pertinently,and the conclusions provide guidance for the design and construction of up lift piles in the actual engineer.展开更多
This paper reports in situ tension test and laboratory model test for large diameter, manually digging anchorage piles in the 2nd Luzhou Changjiang Bridge. Tension behavior, uplift bearing capacity and influenc...This paper reports in situ tension test and laboratory model test for large diameter, manually digging anchorage piles in the 2nd Luzhou Changjiang Bridge. Tension behavior, uplift bearing capacity and influence of rock characteristics on bearing capacity are discussed. Proposes are presented with respect to issues related to the construction and design of uplift piles.展开更多
To optimize the distance between the bells in pile design,this paper reports a series of small scale tests on the uplift capacity of double belled piles embedded in dry dense sand considering different bell space rati...To optimize the distance between the bells in pile design,this paper reports a series of small scale tests on the uplift capacity of double belled piles embedded in dry dense sand considering different bell space ratios.Finite element modelling is also performed to evaluate the range of soil failure around the piles during pile uplift displacement.Test results show that when bell space ratio is 6 or 8,the uplift capacity reaches the peak value.The upper bell bears more load than the lower one for the piles with bell space ratio less than 6,while the lower bell bears more load than the upper one for the piles with bell space ratio larger than 8.展开更多
It is disclosed a method for the stability analysis of foundation piles and piers subjected to lateral loading, both static and seismic conditions. The stability analysis for stratified soil is based upon the models o...It is disclosed a method for the stability analysis of foundation piles and piers subjected to lateral loading, both static and seismic conditions. The stability analysis for stratified soil is based upon the models of foundation soil-structure interaction and the Rankine＇s theory of earth passive pressure. In addition, its application is simpler and it can be solved using a spreadsheet. The procedure described in this work can be used in homogeneous soils as in stratified soils, considers the horizontal drag forces exerted by the soil mass against the foundation during an earthquake, can be used easily in the four pile and piers boundary cases, and considers the pore pressure generated in a fine saturated soil during an earthquake or during a rapid application of the horizontal load. The solution of two examples are shown, one in static condition and one in seismic condition, detailing the procedure step by step.展开更多
文摘Based on Mindlin stress solution, a numerical computational method was proposed to calculate the stresses in the ground induced by side friction and the resistance of Y-shaped vibro-pile. The improved Terzaghi's and ЪерезанцевВГ's methods for ultimate bearing capacity evaluation were proposed by considering the stress strength induced by friction resistance at pile head level of Y-pile. A new method to calculate the ultimate bearing capacity of Y-pile was also proposed based on the assumptions of soil failure mode at the tip of Y-pile and the use of Mohr-Coulomb soil yield criterion and Vesic compressive correction coefficient with the induced stresses in the ground. Based on the comparisons with the field static load test results, it is found that the improved Terzaghi's method gives higher ultimate capacity, while the other two methods shows good agreement with the field results.
基金This work was supported by National Key Research,Development Project of China(2016YFC0802206)Disaster Prevention and Mitigation Collaborative Innovation Center for Large Infrastructure of Hebei Province(2017),and Postgraduate Innovative Funding Projects of Hebei Province(CXZZSS2018060).
文摘The buoyancy of groundwater can reduce the foundation bearing capa-city and cause the metro tunnels to float as a whole,which threatens the safety of structures seriously.Therefore,uplift piles are set up to improve the structural sta-bility.In this paper,FLAC3D software is used to establish the calculation models of pile foundation.The bearing failure process of uplift piles was simulated to study the influencing factors on single pile load bearing capacity as well as the cooperative work laws of pile groups.The load-displacement curves of pile top under different length-diameter ratios,pile soil interface characteristics and pile types are obtained,respectively.The results showed that,increasing the length-diameter ratio and the pile-soil interface roughness properdly can improve the bear-ing capacity of uplift piles.Besides,changing the shapes of constant pile section can also improve it,which has the most significant effect concerning of saving material cost.In the loading process of pile groups,the ultimate bearing capacity of corner pile is the biggest,the side pile is the next,and the center pile is the smallest.The de formation characteristics of pile top are as follows:the center pile is the biggest,the side pile is the next,and comer pile is the smallest.Combined with the results,the uplift resistance of group piles can be enhanced pertinently,and the conclusions provide guidance for the design and construction of up lift piles in the actual engineer.
文摘This paper reports in situ tension test and laboratory model test for large diameter, manually digging anchorage piles in the 2nd Luzhou Changjiang Bridge. Tension behavior, uplift bearing capacity and influence of rock characteristics on bearing capacity are discussed. Proposes are presented with respect to issues related to the construction and design of uplift piles.
基金Project(51778346) supported by the National Natural Science Foundation of ChinaProject(2019GSF111007) supported by the Key Research and Development Project of Shandong Province of China+1 种基金Project(ZR201808040034) supported by the Natural Science Foundation of Shandong Province of ChinaProject(2015RCJJ010) supported by the Talent Introduction Research Start-up Fund Project of Shandong University of Science and Technology,China。
文摘To optimize the distance between the bells in pile design,this paper reports a series of small scale tests on the uplift capacity of double belled piles embedded in dry dense sand considering different bell space ratios.Finite element modelling is also performed to evaluate the range of soil failure around the piles during pile uplift displacement.Test results show that when bell space ratio is 6 or 8,the uplift capacity reaches the peak value.The upper bell bears more load than the lower one for the piles with bell space ratio less than 6,while the lower bell bears more load than the upper one for the piles with bell space ratio larger than 8.
文摘It is disclosed a method for the stability analysis of foundation piles and piers subjected to lateral loading, both static and seismic conditions. The stability analysis for stratified soil is based upon the models of foundation soil-structure interaction and the Rankine＇s theory of earth passive pressure. In addition, its application is simpler and it can be solved using a spreadsheet. The procedure described in this work can be used in homogeneous soils as in stratified soils, considers the horizontal drag forces exerted by the soil mass against the foundation during an earthquake, can be used easily in the four pile and piers boundary cases, and considers the pore pressure generated in a fine saturated soil during an earthquake or during a rapid application of the horizontal load. The solution of two examples are shown, one in static condition and one in seismic condition, detailing the procedure step by step.
