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Elastic solutions for partially embedded single piles subjected to simultaneous axial and lateral loading 被引量:4
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作者 张磊 龚晓南 俞建霖 《Journal of Central South University》 SCIE EI CAS 2014年第11期4330-4337,共8页
In order to improve the design level of partially embedded single piles under simultaneous axial and lateral loads, the differential solutions were deduced, in which the soil was treated as an ideal, elastic, homogene... In order to improve the design level of partially embedded single piles under simultaneous axial and lateral loads, the differential solutions were deduced, in which the soil was treated as an ideal, elastic, homogeneous, semi-infinite isotropic medium. A comparison was made between model test results and the obtained solutions to show their validity. The calculation results indicate that the horizontal displacement and bending moment of the pile increase with increases of the axial and lateral loads. The maximum horizontal displacement and bending moment decrease by 37.9% and 13.9%, respectively, when the elastic modulus of soil increases from 4 MPa to 20 MPa. The Poisson ratio of soil plays a marginal role in pile responses. There is a critical pile length under the ground, beyond which the pile behaves as though it was infinitely long. The presented solutions can make allowance for the continuous nature of soil, and if condition permits, they can approach exact ones. 展开更多
关键词 pile-soil interaction simultaneous axial and lateral loads difference method elastic modulus displacement
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Numerical simulation of influences of the earth medium's lateral heterogeneity on co- and post-seismic deformation 被引量:3
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作者 Xu Bei Xu Caijun 《Geodesy and Geodynamics》 2015年第1期46-54,共9页
Many studies revealed that the Earth medium's lateral heterogeneity can cause considerable effects on the co- and post-seismic deformation field. In this study, the threedimensional finite element numerical method ar... Many studies revealed that the Earth medium's lateral heterogeneity can cause considerable effects on the co- and post-seismic deformation field. In this study, the threedimensional finite element numerical method are adopted to quantify the effects of lateral heterogeneity caused by material parameters and fault dip angle on the co- and postseismic deformation in the near- and far-field. Our results show that: 1) the medium's lateral heterogeneity does affect the co-seismic deformation, with the effects increasing with the medium's lateral heterogeneity caused by material parameters; 2) the Lame parameters play a more dominant role than density in the effects caused by lateral heterogeneity; 3) when a fault's dip angle is smaller than 90, the effects of the medium's lateral heterogeneity on the hanging wall are greater than on the footwall; 4) the impact of lateral heterogeneity caused by the viscosity coefficient on the post-seismic deformation can affect a large area, including the near- and far-field. 展开更多
关键词 Finite element method Medium s lateral heterogeneity Numerical simulation Co-seismic deformation Post-seismic deformation Geod
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Simple analytical model for depth-averaged velocity in meandering compound channels 被引量:3
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作者 Yuqi SHAN Chao LIU Maokang LUO 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2015年第6期707-718,共12页
A simple but applicable analytical model is presented to predict the lat- eral distribution of the depth-averaged velocity in meandering compound channels. The governing equation with curvilinear coordinates is derive... A simple but applicable analytical model is presented to predict the lat- eral distribution of the depth-averaged velocity in meandering compound channels. The governing equation with curvilinear coordinates is derived from the momentum equation and the flow continuity equation under the condition of quasi-uniform flow. A series of experiments are conducted in a large-scale meandering compound channel. Based on the experimental data, a magnitude analysis is carried out for the governing equation, and two lower-order shear stress terms are ignored. Four groups of experimental data from different sources are used to verify the predictive capability of this model, and good predictions are obtained. Finally, the determination of the velocity parameter and the limitation of this model are discussed. 展开更多
关键词 meandering compound channel simple analytical model lateral distribu-tion method physical experiment depth-averaged velocity
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大鼠外侧巨细胞旁网状核的传出纤维联系——HRP法研究
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作者 田启 周敬修 《神经解剖学杂志》 CAS CSCD 北大核心 1989年第2期209-212,共4页
用HRP轴■顺、逆行追踪法观察了大鼠外侧巨细胞旁网状核(PGCL)的传出纤维联系。结果表明:①PGCL经轴■顺行传递,可投射到与痛觉及其调控有关的核团,如脊髓背角、三叉神经脊束核、导水管周围灰质、束旁核、外侧颈核、脑干网状结构核群等;... 用HRP轴■顺、逆行追踪法观察了大鼠外侧巨细胞旁网状核(PGCL)的传出纤维联系。结果表明:①PGCL经轴■顺行传递,可投射到与痛觉及其调控有关的核团,如脊髓背角、三叉神经脊束核、导水管周围灰质、束旁核、外侧颈核、脑干网状结构核群等;PGCL还投射到与调节内脏活动有关的孤束核、迷走神经背核、导水管周围灰质背份、臂旁核、脊髓侧角等;也向三叉神经运动核、下丘等处发出投射纤维。②腰髓注射HRP后,在PGCL中见有较多的标记细胞,主要分布在锥体束外侧和面神经核腹内侧区域,部分细胞亦见于锥体束内及PGCL靠近软脑膜处。③向下丘和孤束核注入HRP以作往返印证,在PGCL见到标记细胞和纤维。 展开更多
关键词 外侧巨细胞旁 网状核 传出纤维联系
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Automated pavement horizontal curve measurement methods based on inertial measurement unit and 3D profiling data 被引量:8
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作者 Wenting Luo Lin Li Kelvin C.P.Wang 《Journal of Traffic and Transportation Engineering(English Edition)》 2016年第2期137-145,共9页
Pavement horizontal curve is designed to serve as a transition between straight segments, and its presence may cause a series of driving-related safety issues to motorists and drivers. As is recognized that traditiona... Pavement horizontal curve is designed to serve as a transition between straight segments, and its presence may cause a series of driving-related safety issues to motorists and drivers. As is recognized that traditional methods for curve geometry investigation are time consuming, labor intensive, and inaccurate, this study attempts to develop a method that can automatically conduct horizontal curve identification and measurement at network level. The digital highway data vehicle (DHDV) was utilized for data collection, in which three Euler angles, driving speed, and acceleration of survey vehicle were measured with an inertial measurement unit (IMU). The 3D profiling data used for cross slope calibration was obtained with PaveVision3D Ultra technology at 1 mm resolution. In this study, the curve identification was based on the variation of heading angle, and the curve radius was calculated with ki- nematic method, geometry method, and lateral acceleration method. In order to verify the accuracy of the three methods, the analysis of variance (ANOVA) test was applied by using the control variable of curve radius measured by field test. Based on the measured curve radius, a curve safety analysis model was used to predict the crash rates and safe driving speeds at horizontal curves. Finally, a case study on 4.35 km road segment demonstrated that the proposed method could efficiently conduct network level analysis. 展开更多
关键词 Horizontal curve Inertial measurement unit (IMU) Curve radius Kinematic method Geometry method lateral acceleration method ANOVA test Curve safety analysis
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