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沉降 9

DX桩 8

承载力 4

高速铁路 3

数值分析 2

随机微分方程 2

DPP);分布式功率转换器;开关电容转换器 1

DX旋挖挤扩灌注桩 1

MPPT);差分功率处理(Differential power processing 1

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串联内阻 1

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京津城际铁路 1

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区域性沉降对高速铁路基础设施影响的研究

康高亮

《工程(英文)》 2016年 第2卷 第3期   页码 374-379 doi: 10.1016/J.ENG.2016.03.014

摘要:

本文对高速铁路线路基础沉降及差异沉降的主要影响因素进行了分析,提出局部地下水开采是影响线路差异沉降的直接诱因。通过对不同差异沉降量下无砟轨道附加荷载及高速行车过程中车辆、轨道和桥梁动力响应的研究,初步提出了运营期线路基础差异沉降控制标准。

关键词: 区域沉降     差异沉降     无砟轨道附加荷载     车辆&ndash     轨道动力学    

Predicting the response of continuous RC deep beams under varying levels of differential settlement

M. Z. NASER, R. A. HAWILEH

《结构与土木工程前沿(英文)》 2019年 第13卷 第3期   页码 686-700 doi: 10.1007/s11709-018-0506-2

摘要: This paper investigates the effect of differential support settlement on shear strength and behavior of continuous reinforced concrete (RC) deep beams. A total of twenty three-dimensional nonlinear finite element models were developed taking into account various constitutive laws for concrete material in compression (crushing) and tension (cracking), steel plasticity (i.e., yielding and strain hardening), bond-slip at the concrete and steel reinforcement interface as well as unique behavior of spring-like support elements. These models are first validated by comparing numerical predictions in terms of load-deflection response, crack propagation, reaction distribution, and failure mode against that of measured experimental data reported in literature. Once the developed models were successfully validated, a parametric study was designed and performed. This parametric study examined number of critical parameters such as ratio and spacing of the longitudinal and vertical reinforcement, compressive and tensile strength of concrete, as well as degree (stiffness) and location of support stiffness to induce varying levels of differential settlement. This study also aims at presenting a numerical approach using finite element simulation, supplemented with coherent assumptions, such that engineers, practitioners, and researchers can carry out simple, but yet effective and realistic analysis of RC structural members undergoing differential settlements due to variety of load actions.

关键词: concrete     continuous beams     deep beams     finite element modeling     support settlement    

Prediction of shield tunneling-induced ground settlement using machine learning techniques

Renpeng CHEN, Pin ZHANG, Huaina WU, Zhiteng WANG, Zhiquan ZHONG

《结构与土木工程前沿(英文)》 2019年 第13卷 第6期   页码 1363-1378 doi: 10.1007/s11709-019-0561-3

摘要: Predicting the tunneling-induced maximum ground surface settlement is a complex problem since the settlement depends on plenty of intrinsic and extrinsic factors. This study investigates the efficiency and feasibility of six machine learning (ML) algorithms, namely, back-propagation neural network, wavelet neural network, general regression neural network (GRNN), extreme learning machine, support vector machine and random forest (RF), to predict tunneling-induced settlement. Field data sets including geological conditions, shield operational parameters, and tunnel geometry collected from four sections of tunnel with a total of 3.93 km are used to build models. Three indicators, mean absolute error, root mean absolute error, and coefficient of determination the ( ) are used to demonstrate the performance of each computational model. The results indicated that ML algorithms have great potential to predict tunneling-induced settlement, compared with the traditional multivariate linear regression method. GRNN and RF algorithms show the best performance among six ML algorithms, which accurately recognize the evolution of tunneling-induced settlement. The correlation between the input variables and settlement is also investigated by Pearson correlation coefficient.

关键词: EPB shield     shield tunneling     settlement prediction     machine learning    

Tuned reactive power dispatch through modified differential evolution technique

S. BISWAS (RAHA), N. CHAKRABORTY

《能源前沿(英文)》 2012年 第6卷 第2期   页码 138-147 doi: 10.1007/s11708-012-0188-8

摘要: This paper explores the capability of modified differential evolution (MDE) technique for solving the reactive power dispatch (RPD) problem. The proposed method is based on the basic differential evolution (DE) technique with a few modifications made into it. DE is one of the strongest optimization techniques though it suffers from the problem of slow convergence while global minima appear. The proposed modifications are tried to resolve the problem. The RPD problem mainly defines loss minimization with stable voltage profile. To solve the RPD problem, the generator bus voltage, transformer tap setting and shunt capacitor placements are controlled by the MDE approach. In this paper, IEEE 14-bus and IEEE 30-bus systems are chosen for MDE implementation. The applied modification show much improved result in comparison to normal DE technique. Comparative study with other soft-computing technique including DE validates the effectiveness of the proposed method.

关键词: reactive power dispatch (RPD)     modified differential evolution (MDE)     differential evolution algorithm with localizations around the best vector (DELB)    

Long-term settlement behavior of ground around shield tunnel due to leakage of water in soft deposit

Huaina WU, Yeshuang XU, Shui-long SHEN, Jin-chun CHAI

《结构与土木工程前沿(英文)》 2011年 第5卷 第2期   页码 194-198 doi: 10.1007/s11709-011-0105-y

摘要: The lining of shield tunnel is usually composed of segments, in which the joints, cracks, and the grouting holes (hereafter called lining deficit) exist. During the long-term running, soils and groundwater may leak from these kinds of lining deficit. The leaking of soil and groundwater causes the long-term ground loss around tunnel and thus results in the settlement of ground surface. This paper aims to analyze the impact of the leakage of groundwater through segments on the long-term settlement of ground surface. The adopted analytical method is based on the theory of groundwater seepage by using numerical simulation. The analyzed results show that settlement of ground surface increases gradually with the increase of the leaked volume of tunnel segments. When the leaked volume was unevenly distributed, differential settlement occurred locally. Comparative analysis by changing the leaked volume was conducted. The results reveal that there is a linear relationship between settlement and leaked volume when the leaked volume was controlled within the allowable limit.

关键词: lining deficit     leakage of water     shield tunnel     settlement     soft deposit    

Review of MEMS differential scanning calorimetry for biomolecular study

Shifeng YU, Shuyu WANG, Ming LU, Lei ZUO

《机械工程前沿(英文)》 2017年 第12卷 第4期   页码 526-538 doi: 10.1007/s11465-017-0451-0

摘要:

Differential scanning calorimetry (DSC) is one of the few techniques that allow direct determination of enthalpy values for binding reactions and conformational transitions in biomolecules. It provides the thermodynamics information of the biomolecules which consists of Gibbs free energy, enthalpy and entropy in a straightforward manner that enables deep understanding of the structure function relationship in biomolecules such as the folding/unfolding of protein and DNA, and ligand bindings. This review provides an up to date overview of the applications of DSC in biomolecular study such as the bovine serum albumin denaturation study, the relationship between the melting point of lysozyme and the scanning rate. We also introduce the recent advances of the development of micro-electro-mechanic-system (MEMS) based DSCs.

关键词: differential scanning calorimetry     biomolecule     MEMS     thermodynamic    

Reliability-based settlement analysis of embankments over soft soils reinforced with T-shaped deep cement

Chana PHUTTHANANON; Pornkasem JONGPRADIST; Daniel DIAS; Xiangfeng GUO; Pitthaya JAMSAWANG; Julien BAROTH

《结构与土木工程前沿(英文)》 2022年 第16卷 第5期   页码 638-656 doi: 10.1007/s11709-022-0825-1

摘要: This paper presents a reliability-based settlement analysis of T-shaped deep cement mixing (TDM) pile-supported embankments over soft soils. The uncertainties of the mechanical properties of the in-situ soil, pile, and embankment, and the effect of the pile shape are considered simultaneously. The analyses are performed using Monte Carlo Simulations in combination with an adaptive Kriging (using adaptive sampling algorithm). Individual and system failure probabilities, in terms of the differential and maximum settlements (serviceability limit state (SLS) requirements), are considered. The reliability results for the embankments supported by TDM piles, with various shapes, are compared and discussed together with the results for conventional deep cement mixing pile-supported embankments with equivalent pile volumes. The influences of the inherent variabilities in the material properties (mean and coefficient of variation values) on the reliability of the piled embankments, are also investigated. This study shows that large TDM piles, particularly those with a shape factor of greater than 3, can enhance the reliability of the embankment in terms of SLS requirements, and even avoid unacceptable reliability levels caused by variability in the material properties.

关键词: T-shaped deep cement mixing piles     piled embankments     settlement     reliability analysis     soil uncertainties    

Finite element prediction on the response of non-uniformly arranged pile groups considering progressive failure of pile-soil system

Qian-Qing ZHANG, Shan-Wei LIU, Ruo-Feng FENG, Jian-Gu QIAN, Chun-Yu CUI

《结构与土木工程前沿(英文)》 2020年 第14卷 第4期   页码 961-982 doi: 10.1007/s11709-020-0632-5

摘要: A uniform arrangement of individual piles is commonly adopted in the conventional pile group foundation, and basin-shaped settlement is often observed in practice. Large differential settlement of pile groups will decrease the use-safety requirements of building, even cause the whole-building tilt or collapse. To reduce differential settlement among individual piles, non-uniformly arranged pile groups can be adopted. This paper presents a finite element analysis on the response of pile groups with different layouts of individual piles in pile groups. Using the user-defined subroutine FRIC as the secondary development platform, a softening model of skin friction and a hyperbolic model of end resistance are introduced into the contact pair calculation of ABAQUS software. As to the response analysis of a single pile, the reliability of the proposed secondary development method of ABAQUS software is verified using an iterative computer program. The reinforcing effects of individual piles is then analyzed using the present finite element analysis. Furthermore, the response of non-uniformly arranged pile groups, e.g., individual piles with variable length and individual piles with variable diameter, is analyzed using the proposed numerical analysis method. Some suggestions on the layout of individual piles are proposed to reduce differential settlement and make full use of the bearing capacity of individual piles in pile groups for practical purposes.

关键词: numerical simulation     non-uniformly arranged pile groups     differential settlement     pile-soil interaction    

DX桩单桩沉降的理论计算研究

欧阳义,陈立宏,张德华

《中国工程科学》 2012年 第14卷 第1期   页码 74-79

摘要:

DX桩由于承力盘的存在,改变了桩的荷载传递机理,在提高承载力的同时,沉降变形也显著减小。在桩的现场试验基础上,分析了DX桩与等截面桩的桩顶荷载的分配特性,进而依据Mindlin解和Geddes解求解桩端土的附加应力,编制了相应的程序,计算结果表明在同样的荷载条件下,DX桩的沉降是等截面桩的0.55~0.80倍,并对承力盘的变化引起的DX桩的沉降变化进行了分析。

关键词: DX桩     承力盘     沉降     附加应力    

DX桩单桩沉降分析

唐松涛,袁希雨,陈立宏

《中国工程科学》 2012年 第14卷 第1期   页码 41-45

摘要:

DX桩作为变截面桩型的典型代表,具有与普通直孔灌注桩不同的荷载传递机理,使桩基的承载力大大提高,沉降变形显著减小。多点支承的特点使得DX桩的沉降机理变得十分复杂,计算分析困难。通过对DX单桩沉降的实例分析,对DX桩与直孔桩的沉降特性进行对比,验证了设计规程中DX桩的沉降计算公式和修正系数的可靠性。

关键词: DX桩     直孔桩     沉降     修正系数    

Solving multi-objective optimal power flow problem considering wind-STATCOM using differential evolution

Belkacem MAHDAD, K. SRAIRI

《能源前沿(英文)》 2013年 第7卷 第1期   页码 75-89 doi: 10.1007/s11708-012-0222-x

摘要: In this paper, a simple strategy based differential evolution was proposed for solving the problem of multi-objective environmental optimal power flow considering a hybrid model (Wind-Shunt-FACTS). The DE algorithm optimized simultaneously a combined vector control based active power of wind sources and reactive power of multi STATCOM exchanged with the electrical power system to minimize fuel cost and emissions. The proposed strategy was examined and applied to the standard IEEE 30-bus with smooth cost function to solve the problem of security environmental economic dispatch considering multi distributed hybrid model based wind and STATCOM controllers. In addition, the proposed approach was validated on a large practical electrical power system 40 generating units considering valve point effect. Simulation results demonstrate that choosing the installation of multi type of FACTS devices in coordination with many distributed wind sources is a vital research area.

关键词: differential evolution     multi-objective function     optimal power flow     economic dispatch     valve point effect     environment     wind source     STATCOM    

山水城市——21世纪中国的人居环境

鲍世行

《中国工程科学》 2002年 第4卷 第9期   页码 19-23

摘要:

20世纪90年代,中国掀起了一场关于21世纪社会主义中国城市发展模式的大讨论。钱学森教授提出的山水城市概念是把中国传统文化中的山水诗词、山水画和中国古典园林与现代城市建设结合起来。山水城市的核心思想是,兼顾城市生态和历史文化,兼顾现代科技和环境美学;它考虑未来城市生产、生活发展的需要;它是为中国老百姓享受的生活、工作环境。21世纪是城市的世纪,主要是发展中国家的城市化。中国已经开始进入城市化高速发展的时期,世界关注中国城市化发展的道路。这是山水城市讨论的时代背景。中华民族对山水有特殊的感情,山水意识几乎融入中华民族的遗传基因,山水文化的特色之一是综合艺术,这是山水城市的文化背景。

关键词: 山水城市     钱学森     人居环境    

Cluster voltage control method for “Whole County” distributed photovoltaics based on improved differential

《能源前沿(英文)》   页码 782-795 doi: 10.1007/s11708-023-0905-8

摘要: China is vigorously promoting the “whole county promotion” of distributed photovoltaics (DPVs). However, the high penetration rate of DPVs has brought problems such as voltage violation and power quality degradation to the distribution network, seriously affecting the safety and reliability of the power system. The traditional centralized control method of the distribution network has the problem of low efficiency, which is not practical enough in engineering practice. To address the problems, this paper proposes a cluster voltage control method for distributed photovoltaic grid-connected distribution network. First, it partitions the distribution network into clusters, and different clusters exchange terminal voltage information through a “virtual slack bus.” Then, in each cluster, based on the control strategy of “reactive power compensation first, active power curtailment later,” it employs an improved differential evolution (IDE) algorithm based on Cauchy disturbance to control the voltage. Simulation results in two different distribution systems show that the proposed method not only greatly improves the operational efficiency of the algorithm but also effectively controls the voltage of the distribution network, and maximizes the consumption capacity of DPVs based on qualified voltage.

关键词: distributed photovoltaics (DPVs)     cluster partitioning     improved differential evolution algorithm     voltage control     consumption capacity of distributed photovoltaics    

京津城际铁路桥梁沉降观测与评估技术

丁愿文

《中国工程科学》 2009年 第11卷 第1期   页码 43-47

摘要:

以京津城际铁路工程为例,系统地介绍了无碴轨道客运专线(高速铁路)桥梁沉降观测的具体要求、方法,并提出了沉降评估的数学模型和判定条件。

关键词: 京津城际铁路     桥梁     沉降观测     评估    

Scrutiny of non-linear differential equations Euler-Bernoulli beam with large rotational deviation by

M. R. AKBARI,M. NIMAFAR,D. D. GANJI,M. M. AKBARZADE

《机械工程前沿(英文)》 2014年 第9卷 第4期   页码 402-408 doi: 10.1007/s11465-014-0316-8

摘要:

The kinematic assumptions upon which the Euler-Bernoulli beam theory is founded allow it to be extended to more advanced analysis. Simple superposition allows for three-dimensional transverse loading. Using alternative constitutive equations can allow for viscoelastic or plastic beam deformation. Euler-Bernoulli beam theory can also be extended to the analysis of curved beams, beam buckling, composite beams and geometrically nonlinear beam deflection. In this study, solving the nonlinear differential equation governing the calculation of the large rotation deviation of the beam (or column) has been discussed. Previously to calculate the rotational deviation of the beam, the assumption is made that the angular deviation of the beam is small. By considering the small slope in the linearization of the governing differential equation, the solving is easy. The result of this simplification in some cases will lead to an excessive error. In this paper nonlinear differential equations governing on this system are solved analytically by Akbari-Ganji’s method (AGM). Moreover, in AGM by solving a set of algebraic equations, complicated nonlinear equations can easily be solved and without any mathematical operations such as integration solving. The solution of the problem can be obtained very simply and easily. Furthermore, to enhance the accuracy of the results, the Taylor expansion is not needed in most cases via AGM manner. Also, comparisons are made between AGM and numerical method (Runge-Kutta 4th). The results reveal that this method is very effective and simple, and can be applied for other nonlinear problems.

关键词: AGM     critical load of columns     large deformations of beam     nonlinear differential equation    

标题 作者 时间 类型 操作

区域性沉降对高速铁路基础设施影响的研究

康高亮

期刊论文

Predicting the response of continuous RC deep beams under varying levels of differential settlement

M. Z. NASER, R. A. HAWILEH

期刊论文

Prediction of shield tunneling-induced ground settlement using machine learning techniques

Renpeng CHEN, Pin ZHANG, Huaina WU, Zhiteng WANG, Zhiquan ZHONG

期刊论文

Tuned reactive power dispatch through modified differential evolution technique

S. BISWAS (RAHA), N. CHAKRABORTY

期刊论文

Long-term settlement behavior of ground around shield tunnel due to leakage of water in soft deposit

Huaina WU, Yeshuang XU, Shui-long SHEN, Jin-chun CHAI

期刊论文

Review of MEMS differential scanning calorimetry for biomolecular study

Shifeng YU, Shuyu WANG, Ming LU, Lei ZUO

期刊论文

Reliability-based settlement analysis of embankments over soft soils reinforced with T-shaped deep cement

Chana PHUTTHANANON; Pornkasem JONGPRADIST; Daniel DIAS; Xiangfeng GUO; Pitthaya JAMSAWANG; Julien BAROTH

期刊论文

Finite element prediction on the response of non-uniformly arranged pile groups considering progressive failure of pile-soil system

Qian-Qing ZHANG, Shan-Wei LIU, Ruo-Feng FENG, Jian-Gu QIAN, Chun-Yu CUI

期刊论文

DX桩单桩沉降的理论计算研究

欧阳义,陈立宏,张德华

期刊论文

DX桩单桩沉降分析

唐松涛,袁希雨,陈立宏

期刊论文

Solving multi-objective optimal power flow problem considering wind-STATCOM using differential evolution

Belkacem MAHDAD, K. SRAIRI

期刊论文

山水城市——21世纪中国的人居环境

鲍世行

期刊论文

Cluster voltage control method for “Whole County” distributed photovoltaics based on improved differential

期刊论文

京津城际铁路桥梁沉降观测与评估技术

丁愿文

期刊论文

Scrutiny of non-linear differential equations Euler-Bernoulli beam with large rotational deviation by

M. R. AKBARI,M. NIMAFAR,D. D. GANJI,M. M. AKBARZADE

期刊论文