期刊文献+
共找到1,048篇文章
< 1 2 53 >
每页显示 20 50 100
Application of Converted Displacement for Modal Parameter Identification of Offshore Wind Turbines with High-Pile Foundation
1
作者 LI Ying WANG Bin +2 位作者 LIU Qiang GAO Shan LU Sujie 《Journal of Ocean University of China》 SCIE CAS CSCD 2022年第6期1467-1478,共12页
In the actual measurement of offshore wind turbines(OWTs),the measured accelerations usually contain a large amount of noise due to the complex and harsh marine environment,which is not conducive to the identification... In the actual measurement of offshore wind turbines(OWTs),the measured accelerations usually contain a large amount of noise due to the complex and harsh marine environment,which is not conducive to the identification of structural modal parameters.For OWTs with remarkably low structural modal frequencies,displacements can effectively suppress the high-frequency vibration noise and amplify the low-frequency vibration of the structure.However,finding a reference point to measure structural displacements at sea is difficult.Therefore,only a few studies on the use of dynamic displacements to identify the modal parameters of OWTs with high-pile foundations are available.Hence,this paper develops a displacement conversion strategy to study the modal parameter identification of OWTs with high-pile foundations.The developed strategy can be divided into the following three parts:zero-order correction of measured acceleration,high-pass filtering by the Butterworth polynomial,and modal parameter identification using the calculated displacement.The superiority of the proposed strategy is verified by analyzing a numerical OWT with a high-pile foundation and the measured accelerations from an OWT with a high-pile foundation.The results show that for OWTs with high-pile foundations dominated by low frequencies,the developed strategy of converting accelerations into displacements and then performing modal parameter identification is advantageous to the identification of modal parameters,and the results have high accuracy. 展开更多
关键词 offshore wind turbine high-pile foundation modal parameter identification baseline drift low-frequency noise
下载PDF
Construction parameters of graded sand-gravel foundation on seismic response law of nuclear safety grade underground corridor
2
作者 Yue Li Xunqiang Yin 《Earthquake Research Advances》 CSCD 2022年第4期39-45,共7页
The treatment of soft soil foundation under nuclear safety grade corridors with graded sand and gravel materials has a good development prospect.It is of great engineering value to explore the influence of constructio... The treatment of soft soil foundation under nuclear safety grade corridors with graded sand and gravel materials has a good development prospect.It is of great engineering value to explore the influence of construction parameters of graded sand and gravel foundation on the seismic response of gallery structures.Taking the safety grade underground corridor of a nuclear power plant as the engineering background,the equivalent linear method is used to consider the nonlinear dynamic characteristics of graded sand and gravel.The energy transfer boundary is applied at the truncation boundary to simulate the dissipation effect of scattered wave fluctuation energy and the ground motion input.The thicknessless contact element is introduced to consider the contact effect between the corridor structure and the graded sand and gravel foundation,so as to establish the calculation model of the dynamic interaction between the graded sand and gravel foundation and the corridor structure.Furthermore,the influence of the relative compactness and the foundation treatment depth on the seismic response of the corridor structure is studied,and the calculation results of the acceleration response spectrum and relative displacement of the corridor structure are analyzed.The calculation results show that the two construction parameters have different degrees of influence on the seismic response of corridor structure.The research results can provide reference for the engineering design and construction of underground corridors,and provide technical support for the application of graded gravel materials in soft soil foundation treatment. 展开更多
关键词 nuclear power plants Underground corridor graded sand-gravel foundation Construction parameters Seismic response
下载PDF
TIME DOMAIN PARAMETERS IDENTIFICATION OF FOUNDATION-STRUCTURE INTERACTION SYSTEM
3
作者 黄义 刘增荣 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2005年第7期855-864,共10页
The time domain parameter laenuncauon memoa oi me iounuauon-structure interaction system is presented. On the basis of building the computation mode and the motion equation of the foundation-structure interaction syst... The time domain parameter laenuncauon memoa oi me iounuauon-structure interaction system is presented. On the basis of building the computation mode and the motion equation of the foundation-structure interaction system, the system parameter identification method was established by using the extended Kalman filter (EKF) technique and taking the unknown parameters in the system as the augment state variables. And the time parameter identification process of the foundation-structure interaction system was implemented by using the data of the layer foundation-storehouse interaction system model test on the large vibration platform. The computation result shows that the established parameter identification method can induce good parameter estimation. 展开更多
关键词 foundation-structure interaction system time domain parameter identification
下载PDF
BOUNDARY INTEGRAL EQUATIONS FOR BENDING PROBLEM OF REISSNER'S PLATES ONTWO-PARAMETER FOUNDATION
4
作者 李正良 周永明 邓安福 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1998年第4期351-359,共9页
Two fundamental solutions for bending problem of Reissner's plates on twoparameter foundation are derived by means of Fouier integral transformation of generalized function in this paper.On the basis of virtual wo... Two fundamental solutions for bending problem of Reissner's plates on twoparameter foundation are derived by means of Fouier integral transformation of generalized function in this paper.On the basis of virtual work principles, three boundary integral equations which fit for arbitrary shapes, loads and boundary conditions of thick plates are presented according to Hu Haichang's theory about Reissner's plates. It provides the fundamental theories for the application of BEM. A numerical example is given for clamped, simply supported and free boundary conditions. The results obtained are satisfactory as compared with the analytical methods. 展开更多
关键词 Reissuer's plate two-parameter foundation fundamental solution boundary integral equation
下载PDF
A Unified Dimensionless Parameter for Finite Element Mesh for Beams Resting on Elastic Foundation
5
作者 Ping Lou Xinlei Zhang +2 位作者 F.T.K.Au Zixian Zhang Yi Huang 《Computer Modeling in Engineering & Sciences》 SCIE EI 2020年第3期955-969,共15页
Discretising a structure into elements is a key step in finite element(FE)analysis.The discretised geometry used to formulate an FE model can greatly affect accuracy and validity.This paper presents a unified dimensio... Discretising a structure into elements is a key step in finite element(FE)analysis.The discretised geometry used to formulate an FE model can greatly affect accuracy and validity.This paper presents a unified dimensionless parameter to generate a mesh of cubic FEs for the analysis of very long beams resting on an elastic foundation.A uniform beam resting on elastic foundation with various values of flexural stiffness and elastic supporting coefficients subject to static load and moving load is used to illustrate the application of the proposed parameter.The numerical results show that(a)Even if the values of the flexural stiffness of the beam and elastic supporting coefficient of the elastic foundation are different,the same proposed parameter“s”can ensure the same accuracy of the FE solution,but the accuracy may differ for use of the same element length;(b)The proposed dimensionless parameter“s”can indeed be used as a unified index to generate the mesh for a beam resting on elastic foundation,whereas the use of the same element length as a criterion may be misleading;(c)The errors between the FE and analytical solutions for the maximum vertical displacement,shear force and bending moment of the beam increase with the dimensionless parameter“s”;and(d)For the given allowable errors for the vertical displacement,shear force and bending moment of the beam under static load and moving load,the corresponding values of the proposed parameter are provided to guide the mesh generation. 展开更多
关键词 Beam cubic finite element elastic foundation finite element mesh unified dimensionless parameter.
下载PDF
Parameter Extraction for 2-π Equivalent Circuit Model of RF CMOS Spiral Inductors 被引量:1
6
作者 高巍 余志平 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2006年第4期667-673,共7页
A novel parameter extraction method with rational functions is presented for the 2-πequivalent circuit model of RF CMOS spiral inductors. The final S-parameters simulated by the circuit model closely match experiment... A novel parameter extraction method with rational functions is presented for the 2-πequivalent circuit model of RF CMOS spiral inductors. The final S-parameters simulated by the circuit model closely match experimental data. The extraction strategy is straightforward and can be easily implemented as a CAD tool to model spiral inductors. The resulting circuit models will be very useful for RF circuit designers. 展开更多
关键词 2-π compact model parameters extraction RF CMOS spiral inductors
下载PDF
Analysis model for deformation mechanism of strip foundation of building:Considering shear effect of down-crossing tunnel under excavation 被引量:4
7
作者 WU Ting-yao JIANG Nan +3 位作者 ZHOU Chuan-bo XIA Yu-qing ZHANG Yu-qi ZHU Bin 《Journal of Central South University》 SCIE EI CAS CSCD 2021年第8期2556-2573,共18页
When the tunnel underpasses through the building,it will cause deformation and even damage to the buildings above,and the deformation of building foundation is the key to building safety.Based on the engineering case,... When the tunnel underpasses through the building,it will cause deformation and even damage to the buildings above,and the deformation of building foundation is the key to building safety.Based on the engineering case,the theoretical analysis was employed to evaluate the influence of shield tunnel underpass construction on the stability of the building,and the optimal tunneling parameters in the field construction have been obtained through the verified theoretical model and parameter analysis.First,the strip foundation of the building was simplified to the Timoshenko beam,which was taken into account the shear effect,and then the deformation displacement of the soil at the same place of strip foundation was applied to the simplified Timoshenko beam.Finally,the numerical solution of the displacement of the strip foundation was obtained by using the finite element method and verified its reliability using Euler-Bernoulli beam theoretical model,field monitoring data,and numerical simulation.Parameters analysis for the deformation and internal force of strip foundation under different types of shield machine tunneling parameters showed that the influence of the pressure of shield excavation chamber,thrust of shield,and driving speed played an important role in the deformation of the building’s strip foundation and internal force. 展开更多
关键词 down-crossing tunnel Timoshenko beam strip foundation finite element method parameters analysis
下载PDF
Dynamics and adaptive control of a dual-arm space robot with closed-loop constraints and uncertain inertial parameters 被引量:20
8
作者 Ying-Hong Jia Quan Hu Shi-Jie Xu 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2014年第1期112-124,共13页
A dynamics-based adaptive control approach is proposed for a planar dual-arm space robot in the presence of closed-loop constraints and uncertain inertial parameters of the payload. The controller is capable of contro... A dynamics-based adaptive control approach is proposed for a planar dual-arm space robot in the presence of closed-loop constraints and uncertain inertial parameters of the payload. The controller is capable of controlling the po- sition and attitude of both the satellite base and the payload grasped by the manipulator end effectors. The equations of motion in reduced-order form for the constrained system are derived by incorporating the constraint equations in terms of accelerations into Kane's equations of the unconstrained system. Model analysis shows that the resulting equations perfectly meet the requirement of adaptive controller design. Consequently, by using an indirect approach, an adaptive control scheme is proposed to accomplish position/attitude trajectory tracking control with the uncertain parameters be- ing estimated on-line. The actuator redundancy due to the closed-loop constraints is utilized to minimize a weighted norm of the joint torques. Global asymptotic stability is proven by using Lyapunov's method, and simulation results are also presented to demonstrate the effectiveness of the proposed approach. 展开更多
关键词 Space robot Dynamics. Adaptive control Closed-loop constraint parameter uncertainty - Kane's equation
下载PDF
Stellar parameters of main sequence turn-off star candidates observed with LAMOST and Kepler 被引量:1
9
作者 Ya-Qian Wu Mao-Sheng Xiang +10 位作者 Xian-Fei Zhang Tan-Da Li Shao-Lan Bi Xiao-Wei Liu Jian-Ning Fu Yang Huang Zhi-Jia Tian Kang Liu Zhi-Shuai Ge Xin He Jing-Hua Zhang 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2017年第1期55-70,共16页
Main sequence turn-off (MSTO) stars since their ages can be robustly estimated from have advantages as indicators of Galactic evolution atmospheric parameters. Hundreds of thousands of MSTO stars have been selected ... Main sequence turn-off (MSTO) stars since their ages can be robustly estimated from have advantages as indicators of Galactic evolution atmospheric parameters. Hundreds of thousands of MSTO stars have been selected from the LAMOST Galactic survey to study the evolution of the Galaxy, and it is vital to derive accurate stellar parameters. In this work, we select 150 MSTO star candidates from the MSTO star sample of Xiang that have asteroseismic parameters and determine accurate stellar parameters for these stars by combining asteroseismic parameters deduced from Kepler photometry and atmospheric parameters deduced from LAMOST spectra. With this sample, we examine the age determination as well as the contamination rate of the MSTO star sample. A comparison of age between this work and Xiang shows a mean difference of 0.53 Gyr (7%) and a dispersion of 2.71 Gyr (28%). The results show that 79 of the candidates are MSTO stars, while the others are contaminations from either main sequence or sub-giant stars. The contamination rate for the oldest stars is much higher than that for younger stars. The main cause for the high contamination rate is found to be the relatively large systematic bias in the LAMOST surface gravity estimates. 展开更多
关键词 stars: fundamental parameters - stars evolution - stars ASTEROSEISMOLOGY
下载PDF
Powell dynamic identification of displacement parameters of indeterminate thin-walled curve box based on FCSE theory 被引量:5
10
作者 Jian Zhang Chu-Wei Zhou Jia-Shou Zhuo 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2011年第3期452-460,共9页
The FCSE controlling equation of pinned thinwalled curve box was derived and the indeterminate problem of continuous thin-walled curve box with diaphragm was solved based on flexibility theory. With Bayesian statistic... The FCSE controlling equation of pinned thinwalled curve box was derived and the indeterminate problem of continuous thin-walled curve box with diaphragm was solved based on flexibility theory. With Bayesian statistical theory,dynamic Bayesian error function of displacement parameters of indeterminate curve box was founded. The corresponding formulas of dynamic Bayesian expectation and variance were deduced. Combined with one-dimensional Fibonacci automatic search scheme of optimal step size,the Powell optimization theory was utilized to research the stochastic identification of displacement parameters of indeterminate thin-walled curve box. Then the identification steps were presented in detail and the corresponding calculation procedure was compiled. Through some classic examples,it is obtained that stochastic performances of systematic parameters and systematic responses are simultaneously deliberated in dynamic Bayesian error function. The one-dimensional optimization problem of the optimal step size is solved by adopting Fibonacci search method. And the Powell identification of displacement parameters of indeterminate thin-walled curve box has satisfied numerical stability and convergence,which demonstrates that the presented method and the compiled procedure are correct and reliable.During parameters鈥?iterative processes,the Powell theory is irrelevant with the calculation of finite curve strip element(FCSE) partial differentiation,which proves high computation effciency of the studied method. 展开更多
关键词 Powell theory - Indeterminate curve box . Displacement parameters - Fibonacci search method.Flexibility theory
下载PDF
Investigation of structural parameters and self-aggregation of Algerian asphaltenes in organic solvents 被引量:2
11
作者 Asma Larbi Mortada Daaou Abassia Faraoun 《Petroleum Science》 SCIE CAS CSCD 2015年第3期509-517,共9页
Elemental analysis, Fourier transform infrared (FTIR), 1H-NMR, fluorescence spectroscopy, and surface tension methods have been used to characterize the molecular structure and the aggregation behaviors of two aspha... Elemental analysis, Fourier transform infrared (FTIR), 1H-NMR, fluorescence spectroscopy, and surface tension methods have been used to characterize the molecular structure and the aggregation behaviors of two asphaltenic fractions derived, respectively, from an Alge- rian petroleum well and a corresponding storage tank deposit. Elemental analysis, FTIR, ~H-NMR, and fluores- cence spectroscopy were used to investigate the chemical composition and structural parameters of asphaltenes, while the surface tension method was used to measure the critical micelle concentration (CMC) in organic solvents with different solubility parameters and polarities in order to characterize the asphaltenes' aggregation behaviors. Results show that the unstable asphaltenes fraction extracted from the storage tank deposit possesses a higher polarity (higher heteroatoms content) and a lower aro- maticity than stable asphaltenes from the petroleum well. The CMC results indicate that asphaltenes with high polarity and low aromaticity have a high solubility in polar solvents such as nitrobenzene, whereas asphaltenes with low polarity and high aromaticity are more soluble in solvents with weak polarity, like toluene. It is concludedthat the difference of structure of asphaltene samples and polarity of solvents can lead to difference of aggregation behaviors. 展开更多
关键词 Asphaltenes Algerian petroleum Structural parameters - CMC
下载PDF
Energy Balance-related Behaviors Are Related to Cardiometabolic Parameters and Predict Adiposity in 8-14-year-old Overweight Chinese Children One Year Later 被引量:1
12
作者 LI Liu Bai WANG Nan +4 位作者 WU Xu Long WANG Ling LI Jing Jing YANG Miao MA Jun 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2016年第10期754-757,共4页
To identify target energy balance-related behaviors(ERBs),baseline data from 141overweight or obese schoolchildren(aged 8-14years old)was used to predict adiposity[body mass index(BMI)and fat percentage]one year... To identify target energy balance-related behaviors(ERBs),baseline data from 141overweight or obese schoolchildren(aged 8-14years old)was used to predict adiposity[body mass index(BMI)and fat percentage]one year later.The ERBs included a modified Dietary Approach to Stop Hypertension diet score(DASH score),leisure-time physical activity(PA,days/week),and leisure screen time(minutes/day).Several cardiometabolic variables were measured in the fasting state, including systolic blood pressure (SBP), diastolic blood pressure (DBP), blood glucose (GLU), total cholesterol (TC), triglycerides (TG), low-density lipoprotein (LDL-C), and high-density lipoprotein (HDL-C). 展开更多
关键词 Energy Balance-related Behaviors Are Related to Cardiometabolic parameters and Predict Adiposity in 8-14-year-old Overweight Chinese Children One Year Later BMI body
下载PDF
The W UMa binaries USNO-A2.0 1350-17365531,V471 Cas,V479 Lac and V560 Lac:light curve solutions and global parameters based on Gaia distances 被引量:2
13
作者 Diana P.Kjurkchieva Velimir A.Popov +1 位作者 Yordanka Eneva Nikola I.Petrov 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2019年第1期141-148,共8页
We present photometric observations in Sloan filters g′, i′of the eclipsing W UMa stars USNOA2.0 1350-17365531, V471 Cas, V479 Lac and V560 Lac. The sinusoidal-like O-C diagram of V471 Cas indicates the presence of ... We present photometric observations in Sloan filters g′, i′of the eclipsing W UMa stars USNOA2.0 1350-17365531, V471 Cas, V479 Lac and V560 Lac. The sinusoidal-like O-C diagram of V471 Cas indicates the presence of a third body with mass 0.12 M_⊙(a red dwarf) at distance 897 R_⊙. The O-C diagram of V479 Lac reveals a period decrease of d P/dt =-1.69 × 10-6d yr-1. The results of the light curve solutions are:(i) the targets are overcontact binaries with small fill-out factors;(ii) their components are F–K stars, comparable in size, whose temperature differences are below 80 K;(iii) all targets undergo partial eclipses and to limit the possible mass ratios we carried out two-step q-search analysis. The target global parameters(luminosities, radii, masses) were obtained on the basis of their Gaia distances and the results of our light curve solutions. The obtained total mass of V560 Lac turns out to be smaller than the lower mass limit for presently known W UMa binaries of 1.0-1.2 M_⊙, i.e. this target is a peculiar overcontact system. 展开更多
关键词 binaries:close binaries:eclipsing methods:data analysis stars:fundamental parameterS stars:individual(USNO-A2.0 1350-17365531 V471 Cas V479 Lac V560 Lac)
下载PDF
Estimating Photometric Redshifts with Artificial Neural Networks and Multi-Parameters
14
作者 Li-Li Li Yan-Xia Zhang +1 位作者 Yong-Heng Zhao Da-Wei Yang 《Chinese Journal of Astronomy and Astrophysics》 CSCD 2007年第3期448-456,共9页
We calculate photometric redshifts from the Sloan Digital Sky Survey Data Release 2 (SDSS DR2) Galaxy Sample using artificial neural networks (ANNs). Different input sets based on various parameters (e.g. magnitu... We calculate photometric redshifts from the Sloan Digital Sky Survey Data Release 2 (SDSS DR2) Galaxy Sample using artificial neural networks (ANNs). Different input sets based on various parameters (e.g. magnitude, color index, flux information) are explored. Mainly, parameters from broadband photometry are utilized and their performances in redshift prediction are compared. While any parameter may be easily incorporated in the input, our results indicate that using the dereddened magnitudes often produces more accurate photometric redshifts than using the Petrosian magnitudes or model magnitudes as input, but the model magnitudes are superior to the Petrosian magnitudes. Also, better performance resuits when more effective parameters are used in the training set. The method is tested on a sample of 79 346 galaxies from the SDSS DR2. When using 19 parameters based on the dereddened magnitudes, the rms error in redshift estimation is σz = 0.020184. The ANN is highly competitive tool compared to the traditional template-fitting methods when a large and representative training set is available. 展开更多
关键词 GALAXIES fundamental parameters - techniques photometric - method dataanalysis
下载PDF
Cosmological parameters for spatially flat dust filled Universe in Brans-Dicke theory
15
作者 Gopi Kant Goswami 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2017年第3期55-66,共12页
We have investigated late time acceleration for a spatially fiat dust filled Universe in Brans- Dicke theory in the presence of a positive cosmological constant A. Expressions for Hubble's constant, luminosity distan... We have investigated late time acceleration for a spatially fiat dust filled Universe in Brans- Dicke theory in the presence of a positive cosmological constant A. Expressions for Hubble's constant, luminosity distance and apparent magnitude have been obtained for our model. The theoretical results are compared with observed values of the latest 287 high redshift (0.3 ≤ z ≤1.4) Type Ia supernova data taken from the Union 2.1 compilation to estimate present values of matter and dark energy parame- ters, (Ωm)0 and (ΩA)0. We have also estimated the present value of Hubble's constant H0 in light of an updated sample of Hubble parameter measurements including 19 independent data points. The results are found to be in good agreement with recent astrophysical observations. We also calculated various physical parameters such as matter and dark energy densities, present age of the Universe and decelera- tion parameter. The value for Brans-Dicke-coupling constant ω is set to be 40 000 based on accuracy of solar system tests and recent experimental evidence. 展开更多
关键词 COSMOLOGY osmological parameters - cosmology observations- dark energy-Brans-Dicke theory
下载PDF
Investigations of the electron paramagnetic resonance parameters and the tetragonal local structure for (VCl_6)^(4-) coordination complex in MCl:V^(2+) (M=Na,K,Rb) systems
16
作者 祁林 邝小渝 +2 位作者 柴瑞鹏 段美玲 张彩霞 《Chinese Physics B》 SCIE EI CAS CSCD 2009年第4期1586-1593,共8页
By simulating the electron paramagnetic resonance (EPR) and optical spectra on the basis of the 120 × 120 complete energy matrix, this paper determines the local lattice structure parameters R1 and R2 for MCl... By simulating the electron paramagnetic resonance (EPR) and optical spectra on the basis of the 120 × 120 complete energy matrix, this paper determines the local lattice structure parameters R1 and R2 for MCl:V2+ (M=Na, K, Rb) systems at 77K, 195 K and RT (room temperature 295 K or 302 K), respectively. The theoretical results indicate that there exists a compressed distortion in MCl:V2+ systems. Meanwhile, it finds that the structure parameters R1, R2 and |△R|( = R1 - R2) increase with the rising temperature. Subsequently, from the analysis it concludes that the relation of EPR parameter D vs. △R is approximately linear. Finally, the effects of orbital reduction factor k on the g factors for the three systems have been discussed. 展开更多
关键词 complete energy matrix EPR parameters (VCl6)4- coordination complex local structure
下载PDF
基于PSO-GA-BP神经网络的土体参数反演
17
作者 宋巍 《价值工程》 2024年第14期89-91,共3页
土体参数对于基坑工程数值模拟结果的精度具有重要影响,而随着施工的进行土体参数往往会发生变化,因此为了提高数值模拟的精度,有必要对土体参数进行修正。本文提出一种基于PSO-GA-BP神经网络的土体参数反演方法,该方法旨在利用神经网... 土体参数对于基坑工程数值模拟结果的精度具有重要影响,而随着施工的进行土体参数往往会发生变化,因此为了提高数值模拟的精度,有必要对土体参数进行修正。本文提出一种基于PSO-GA-BP神经网络的土体参数反演方法,该方法旨在利用神经网络的学习和优化能力,对数值模拟中的土体参数进行修正。并通过武汉市12号线中一路地铁站的基坑实际监测数据验证了该方法的准确性和可行性。结果表明:本文提出的PSO-GA-BP神经网络反演方法反演效果良好,修正后的土体参数模拟精度明显提高。 展开更多
关键词 神经网络 数值模拟 超深基坑 参数反演
下载PDF
基于SA-PSO算法优化LS-SVM的基坑土层等效参数反演 被引量:2
18
作者 曹净 唐斌懿 李豪 《工业安全与环保》 2023年第2期15-20,共6页
针对基坑支护结构位移与土层参数具有小样本及非线性的特征,提出一种以模拟退火(SA)算法与粒子群(PSO)算法混合优化最小二乘支持向量机(LSSVM)的位移反分析方法。一是通过均匀试验构造学习与测试样本,运用SA-PSO混合算法对最小二乘支持... 针对基坑支护结构位移与土层参数具有小样本及非线性的特征,提出一种以模拟退火(SA)算法与粒子群(PSO)算法混合优化最小二乘支持向量机(LSSVM)的位移反分析方法。一是通过均匀试验构造学习与测试样本,运用SA-PSO混合算法对最小二乘支持向量机进行参数寻优,寻找模型最优参数组合,并建立最小二乘支持向量机非线性回归模型;二是构建预测位移与实测位移间的目标函数,运用SA-PSO混合算法迭代寻优基坑土层参数值。应用于昆明某实际基坑工程中,反演结果表明此方法具有一定的可行性。 展开更多
关键词 基坑土层 均匀试验 模拟退火-粒子群算法 最小二乘支持向量机 参数反演
下载PDF
Optimization of dewatering schemes for a deep foundation pit near the Yangtze River, China 被引量:5
19
作者 Yang You Changhong Yan +2 位作者 Baotian Xu Shi Liu Canhui Che 《Journal of Rock Mechanics and Geotechnical Engineering》 CSCD 2018年第3期555-566,共12页
A deep foundation pit constructed for an underground transportation hub was excavated near the Yangtze River. Among the strata, there are two confined aquifers, between which lies an aquiclude that is partially missin... A deep foundation pit constructed for an underground transportation hub was excavated near the Yangtze River. Among the strata, there are two confined aquifers, between which lies an aquiclude that is partially missing. To guarantee the safety of pit excavation, the piezometric head of the upper confined aquifer, where the pit bottom is located, should be 1 m below the pit bottom, while that of the lower confined aquifer should be dewatered down to a safe water level to avoid uplift problem. The Yangtze River levee is notably close to the pit, and its deformation caused by dewatering should be controlled. A pumping test was performed to obtain the hydraulic conductivity of the upper confined aquifer. The average value of the hydraulic conductivity obtained from analytical calculation is 20.45 m/d, which is larger than the values from numerical simulation(horizontal hydraulic conductivity K_H = 16 m/d and vertical hydraulic conductivity K_V = S m/d). The difference between K_H and K_V indicates the anisotropy of the aquifer. Two dewatering schemes were designed for the construction and simulated by the numerical models for comparison purposes. The results show that though the first scheme could meet the dewatering requirements, the largest accumulated settlement and differential settlement would be94.64 mm and 3.3‰, respectively, greatly exceeding the limited values. Meanwhile, the second scheme,in which the bottoms of the waterproof curtains in ramp B and the river side of ramp A are installed at a deeper elevation of-28 m above sea level, and 27 recharge wells are set along the levee, can control the deformation of the levee significantly. 展开更多
关键词 Deep foundation pit parameter calculation Dewatering schemes Numerical simulation
下载PDF
Influential Factors of Bucket Foundation for Offshore Wind Turbine 被引量:2
20
作者 丁红岩 刘永刚 +1 位作者 张浦阳 熊康平 《Transactions of Tianjin University》 EI CAS 2015年第3期264-268,共5页
In this paper, the influential design thctors of wide-shallow composite bucket foundation for 3 MW off- shore wind turbine are systematically studied by numerical simulation. The results show that the bucket diameter ... In this paper, the influential design thctors of wide-shallow composite bucket foundation for 3 MW off- shore wind turbine are systematically studied by numerical simulation. The results show that the bucket diameter is larger than 27 m in generak and the range of 7--12 m is appropriate for cylinder height. In particular the bucket foun- dation with diameter of 30 m and cylinder height of 10 m is suitable for most soils. Under ultimate loads, the bucket diameter and elasticity modulus of soil have major effects on the deibrmability of bucket foundation, while the influ- ence of friction coefficient between the bucket and soil is relatively slight. 展开更多
关键词 offshore wind turbine bucket foundation tilt angle soil parameter influential factor
下载PDF
上一页 1 2 53 下一页 到第
使用帮助 返回顶部