O435.2 2000020798小孔成像的光学传递函数分析=Optical transfertunction analysis of a pinhole imaging system[刊,中]/朱海平(丽水师范专科学校物理系.浙江,丽水(323000)),江晓清(浙江大学物理系.浙江,杭州(310028))//光学仪器.-199...O435.2 2000020798小孔成像的光学传递函数分析=Optical transfertunction analysis of a pinhole imaging system[刊,中]/朱海平(丽水师范专科学校物理系.浙江,丽水(323000)),江晓清(浙江大学物理系.浙江,杭州(310028))//光学仪器.-1999,21(3).-12-14根据光学传递函数(OTF),提出一种分析小孔成像最佳位置的方法,小孔成像最佳位置可等效为一个具有"可变光焦度"的薄透镜来确定。参6(吴淑珍)展开更多
A simplified approach is presented for the analysis of the settlement of vertically loaded pile groups. In order to simulate the nonlinear pile-to-pile interaction in pile groups, the soils along the piles are assumed...A simplified approach is presented for the analysis of the settlement of vertically loaded pile groups. In order to simulate the nonlinear pile-to-pile interaction in pile groups, the soils along the piles are assumed to behave as a series of nonlinear springs subjected to the shaft shear stress at the pile/soil interface. Considering the displacement reduction induced by the pile-to-pile interaction, the shear-deformation method is adopted to approximate the displacement field of the layered soils around the piles, and the equivalent stiffness of the springs is obtained. Furthermore, the load-settlement response of pile groups is deduced by modifying the load-transfer functions to account for the pile-to-pile interaction. The settlements of a laboratory pile groups computed by the presented approach are in a good agreement with measured results. The analysis on Contrastive parameters shows that the settlements of pile group decrease with the increase of the pile space and pile length, and the part of piles exceeding the critical pile length has little contribution to the beating capacity of the pile groups.展开更多
A simplified approach is presented to analyze the single pile settlement in multilayered soil. First, a fictitious soil-pile model is employed to consider the effect of layered soil beneath pile toe on pile settlement...A simplified approach is presented to analyze the single pile settlement in multilayered soil. First, a fictitious soil-pile model is employed to consider the effect of layered soil beneath pile toe on pile settlement behavior. Two approximation methods are proposed to simplify the nonlinear load transfer function and simulate the nonlinear compression of fictitious soil-pile, respectively. On this basis, an efficient program is developed. The procedures for determining the main parameters of mathematical model are discussed. Comparisons with two well-documented field experimental pile loading tests are conducted to verify the rationality of the present method. Further studies are also made to evaluate the practicability of the proposed approach when a soft substratum exists, and the results suggest that the proposed method can provide a constructive means for assessing the settlement of a single pile for use in engineering design.展开更多
基金Internationale Stichting Alzheimer Onderzoek(ISAO)grant # 05516 to Jurgen AHR ClaassenNetherlands Heart Foundation grant #2008B113 to Jurgen AHR Claassen+3 种基金Marina ten Damme grant to Aisha SS Meel-van den AbeelenEPSRC(UK)-projects EP/K036157/1EP/G010420/1EP/K036181/1 to Ronney B Panerai and David M Simpson
文摘O435.2 2000020798小孔成像的光学传递函数分析=Optical transfertunction analysis of a pinhole imaging system[刊,中]/朱海平(丽水师范专科学校物理系.浙江,丽水(323000)),江晓清(浙江大学物理系.浙江,杭州(310028))//光学仪器.-1999,21(3).-12-14根据光学传递函数(OTF),提出一种分析小孔成像最佳位置的方法,小孔成像最佳位置可等效为一个具有"可变光焦度"的薄透镜来确定。参6(吴淑珍)
基金Project(50708033) supported by the National Natural Science Foundation of ChinaProjects(200923, CXKJSF0108-2) supported by Transportation Technical Project of Hunan Province, China
文摘A simplified approach is presented for the analysis of the settlement of vertically loaded pile groups. In order to simulate the nonlinear pile-to-pile interaction in pile groups, the soils along the piles are assumed to behave as a series of nonlinear springs subjected to the shaft shear stress at the pile/soil interface. Considering the displacement reduction induced by the pile-to-pile interaction, the shear-deformation method is adopted to approximate the displacement field of the layered soils around the piles, and the equivalent stiffness of the springs is obtained. Furthermore, the load-settlement response of pile groups is deduced by modifying the load-transfer functions to account for the pile-to-pile interaction. The settlements of a laboratory pile groups computed by the presented approach are in a good agreement with measured results. The analysis on Contrastive parameters shows that the settlements of pile group decrease with the increase of the pile space and pile length, and the part of piles exceeding the critical pile length has little contribution to the beating capacity of the pile groups.
基金Project(51378464) supported by the National Natural Science Foundation of China
文摘A simplified approach is presented to analyze the single pile settlement in multilayered soil. First, a fictitious soil-pile model is employed to consider the effect of layered soil beneath pile toe on pile settlement behavior. Two approximation methods are proposed to simplify the nonlinear load transfer function and simulate the nonlinear compression of fictitious soil-pile, respectively. On this basis, an efficient program is developed. The procedures for determining the main parameters of mathematical model are discussed. Comparisons with two well-documented field experimental pile loading tests are conducted to verify the rationality of the present method. Further studies are also made to evaluate the practicability of the proposed approach when a soft substratum exists, and the results suggest that the proposed method can provide a constructive means for assessing the settlement of a single pile for use in engineering design.
