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Field investigation of intelligent compaction for hot mix asphalt resurfacing

Wei HU,Xiang SHU,Baoshan HUANG,Mark WOODS

《结构与土木工程前沿(英文)》 2017年 第11卷 第1期   页码 47-55 doi: 10.1007/s11709-016-0362-x

摘要:

Intelligent compaction (IC) is a relatively new technology for asphalt paving industry. The present study evaluated the effectiveness and potential issues of the IC technology for flexible pavement resurfacing construction using two field projects. In the first project, a geostatistical semivariogram model was established and the parameters derived from it were compared with univariate statistical parameters for the Compaction Meter Value (CMV) data. Further analyses illustrated the effect of temperature on the CMV value and compaction uniformity. In the second project, a multivariate analysis was performed between in situ tests and IC data. The possibility of combining various IC data to predict the asphalt layer density and improve the current quality control and assurance system was discussed.

关键词: intelligent compaction     compaction meter value (CMV)     semivariogram     multivariate analysis    

Experimental research on compaction characteristics of aeolian sand

YUAN Yuqing, WANG Xuancang, ZHOU Xin

《结构与土木工程前沿(英文)》 2008年 第2卷 第4期   页码 359-365 doi: 10.1007/s11709-008-0053-3

摘要: Unlike other road materials, aeolian sand has some compaction characteristics that are key factors in construction qualities of highway in the desert. In order to study the characteristics, a series of laboratory and field tests were performed, including sieve analysis, standard modified compaction, vibrating compaction and field test. By analyzing the sieve analysis test data, it was found that the gradation of aeolian sand was bad, with fine grains whose diameters mostly ranged from 0.25 mm to 0.074 mm. Then, from the laboratory compaction test results, a compaction curve similar to the horizontally-written letter S was obtained. That was quite different from the other kinds of road materials. There were two peak values in the curve with the increase of water content, which was the special characteristic of aeolian sand: to be well compacted whether it was dry or wet. Also, according to laboratory vibrating test results, the best vibrating frequency range was proposed. It was from 45 Hz to 50 Hz. Moreover, some field compaction tests were carried out. On the construction site of the highway, the aeolian sand subgrade was compacted in the condition of natural water content with optimizing construction machines. Its compaction degree reached 96%, meeting the current specifications. At last, comparative studies were carried through with electron microscope. It was shown that the microstructure of compacted dry aeolian sand is much denser than that of the natural one in the field test.

Numerical simulation of compaction parameters for sand-filled embankment using large thickness sand filling

Wentao WANG, Chongzhi TU, Rong LUO

《结构与土木工程前沿(英文)》 2018年 第12卷 第4期   页码 568-576 doi: 10.1007/s11709-017-0444-4

摘要: The study uses the finite element method to simulate a new technique of highway sand embankment filling in Jianghan Plain district, which can raise the thickness of sand-filled layer from 30 cm to 70 cm and can significantly shorten the construction period based on the guarantee of sand embankment construction quality. After simulating the three compacting proposals carried out on the field test, the study uses COMSOL software to research on the compacting effects of sand-filled layers in larger thicknesses by 22 ton vibratory roller alone, and then to investigate the steady compacting effect of 12 ton vibratory roller. The simulation results indicate that the sand-filled layer thickness of 70 cm is suitable for the new sand filling technique, and the sand-filled embankment project with tight construction period is suggested to choose the 12 ton vibration roller for steady compaction.

关键词: sand embankment     compaction in large thickness     numerical simulation     small size vibratory roller     steady compaction    

Nonlinear sealing force of a seawater balance valve used in an 11000-meter manned submersible

《机械工程前沿(英文)》 2023年 第18卷 第1期 doi: 10.1007/s11465-022-0726-y

摘要: Balance valve is a core component of the 11000-meter manned submersible “struggle,” and its sealing performance is crucial and challenging when the maximum pressure difference is 118 MPa. The increasing sealing force improves the sealing performance and increases the system’s energy consumption at the same time. A hybrid analytical–numerical–experimental (ANE) model is proposed to obtain the minimum sealing force, ensuring no leakage at the valve port and reducing energy consumption as much as possible. The effects of roundness error, environmental pressure, and materials on the minimum sealing force are considered in the ANE model. The basic form of minimum sealing force equations is established, and the remaining unknown coefficients of the equations are obtained by the finite element method (FEM). The accuracy of the equation is evaluated by comparing the independent FEM data to the equation data. Results of the comparison show good agreement, and the difference between the independent FEM data and equation data is within 3% when the environmental pressure is 0–118 MPa. Finally, the minimum sealing force equation is applied in a balance valve to be experimented using a deep-sea simulation device. The balance valve designed through the minimum sealing force equation is leak-free in the experiment. Thus, the minimum sealing force equation is suitable for the ultrahigh pressure balance valve and has guiding significance for evaluating the sealing performance of ultrahigh pressure balance valves.

关键词: seawater balance valve     sealing performance     hybrid ANE model     FEM     minimum sealing force equation    

高心墙堆石坝坝面碾压施工仿真理论与应用

钟登华,赵晨生,张平

《中国工程科学》 2011年 第13卷 第12期   页码 28-32

摘要:

在对高心墙堆石坝坝面碾压系统进行全面分析的基础上,提出了以填筑单元为仿真单位的碾压施工仿真理论,建立了能够反映碾压过程中不确定因素的精细化仿真模型,保证仿真贴近实际施工。研究成果在糯扎渡心墙堆石坝工程的填筑单元中得到了应用,验证了方法的可靠性,对于大坝现场碾压施工具有指导意义,为工程进度控制和管理提供了技术支持。

关键词: 高心墙堆石坝     坝面碾压     施工仿真    

Erratum to: Meter-scale variation within a single transect demands attention to taxon accumulation curves

《环境科学与工程前沿(英文)》 2022年 第16卷 第6期 doi: 10.1007/s11783-022-1560-5

A study on fatigue damage of asphalt mixture under different compaction using 3D-microstructural characteristics

Jing HU, Pengfei LIU, Bernhard STEINAUER

《结构与土木工程前沿(英文)》 2017年 第11卷 第3期   页码 329-337 doi: 10.1007/s11709-017-0407-9

摘要: The aim of this paper is investigating the microstructural characteristics of asphalt mixture under different compaction powers. In order to achieve this aim, a test track was built to provide asphalt mixture specimens and X-ray computed tomography (XCT) device was used to scan the internal structure. The aggregate particles and air-voids were extracted using Digital Image Processing (DIP), so the relationship between compaction and air-voids was determined at first, and then, the effect of aggregate particles on the morphology of air-voids can be evaluated, finally, fatigue properties of asphalt mixture with different air-void ratio were measured by indirect tensile fatigue test as well. The research results release the distribution of microstructures in asphalt pavement. 3D fractal dimension is an effective indicator to quantize the complexity of aggregate particles and air-voids; suffering the same compaction power, aggregates cause different constitutions of air-voids in asphalt mixture; investigation in this paper can present the essential relationship between microstructures and fatigue properties.

关键词: asphalt mixture     microstructure     morphology     digital image processing     fatigue damage    

Experimental study on compaction-induced anisotropic mechanical property of rockfill material

Xiangtao ZHANG, Yizhao GAO, Yuan WANG, Yu-zhen YU, Xun SUN

《结构与土木工程前沿(英文)》 2021年 第15卷 第1期   页码 109-123 doi: 10.1007/s11709-021-0693-0

摘要: The anisotropy of rockfill materials has a significant influence on the performance of engineering structures. However, relevant research data are very limited, because of the difficulty with preparing specimens with different inclination angles using traditional methods. Furthermore, the anisotropy test of rockfill materials is complex and complicated, especially for triaxial tests, in which the major principal stress plane intersects with the compaction plane at different angles. In this study, the geometric characteristics of a typical particle fraction consisting of a specific rockfill material were statistically investigated, and the distribution characteristics of particle orientation in specimens prepared via different compaction methods were examined. For high-density rockfill materials, a set of specimen preparation devices for inclined compaction planes was developed, and a series of conventional triaxial compression tests with different principal stress direction angles were conducted. The results reveal that the principal stress direction angle has a significant effect on the modulus, shear strength, and dilatancy of the compacted rockfill materials. Analysis of the relationship between the principal stress direction angles, change in the stress state, and change in the corresponding dominant shear plane shows that the angle between the compacted surface and dominant shear plane is closely related to interlocking resistance associated with the particle orientation. In addition, different principal stress direction angles can change the extent of the particle interlocking effect, causing the specimen to exhibit different degrees of anisotropy.

关键词: rockfill     inclination of specimen preparation     anisotropy     mechanical property     mechanism    

板形计法的定义及实验应用

张进之,段春华,朱健勤

《中国工程科学》 2001年 第3卷 第12期   页码 47-51

摘要:

板形测控数学模型、解析板形刚度理论和板形板厚协调规律的综合称为板形计法。采用两种实验方式验证了板形计法的正确性和实用性,其一是通过轧铝板实验,计算轧机板形刚度和轧件板形刚度,由实测铝板凸度验证板形刚度方程;其二是由CVC板形控制热连轧机实测数据,用离线计算自适应系数的方法验证板形测控数学模型。

关键词: 板形计法     板形刚度方程     测控数学模型     后计算     自适应    

高碾压混凝土坝智能碾压理论研究

刘东海,李丙扬,崔博

《中国工程科学》 2011年 第13卷 第12期   页码 74-79

摘要:

给出了高碾压混凝土坝智能碾压的概念及实现过程,提出了大坝实时监控和智能反馈控制的原理;在实时分析压实指标的基础上,建立了大坝压实质量多元回归模型,进而提出了碾压混凝土坝压实度全仓面实时评价方法;实现了施工过程中碾压机工作性态的自适应调整,确保碾压机速度、激振力、碾压遍数和压实厚度等全过程达标,可有效保证碾压质量,提高施工效率,为碾压混凝土坝建设质量控制提供了一条新的途径。

关键词: 碾压混凝土坝     质量控制     智能碾压     实时监控     质量实时评估    

水下多相流量计在深水油气田开发工程中的应用研究

刘太元,郭宏,郑利军

《中国工程科学》 2012年 第14卷 第11期   页码 69-74

摘要:

科学技术的不断发展,加速了人们对海洋油气勘探向更深的领域迈进。为了实时监测油井井流的变化,以便更好地优化对油藏的开发,水下多相流量计得到了越来越多的应用。概述了目前常见的水下多相流量计的基本测量原理,研究了多相流量计在深水油气田开发应用的影响因素,包括量程、安装位置、通讯结构等,给出了各种不同方案的可能性,对多相流量计在深水油气田开发工程中的应用具有一定的指导意义。

关键词: 深水     水下多相流量计     流动安全     油藏优化     油气田开发    

Intelligent algorithm for optimal meter placement and bus voltage estimation in ring main distribution

L. RAMESH, N. CHAKRABORTY, S. P. CHOWDHURY

《能源前沿(英文)》 2012年 第6卷 第1期   页码 47-56 doi: 10.1007/s11708-011-0159-5

摘要: The advancement in power distribution system poses a great challenge to power engineering researchers on how to best monitor and estimate the state of the distribution network. This paper is executed in two stage processes. The first stage is to identify the optimal location for installation of monitoring instrument with minimal investment cost. The second stage is to estimate the bus voltage magnitude, where real time measurement is conducted and measured through identified meter location which is more essential for decision making in distribution supervisory control and data acquisition system (DSCADA). The hybrid intelligent technique is applied to execute the above two algorithms. The algorithms are tested with institute of electrical and electronics engineers (IEEE) and Tamil Nadu electricity board (TNEB) benchmark systems. The simulated results proves that the swarm tuned artificial neural network (ANN) estimator is best suited for accurate estimation of voltage with different noise levels.

关键词: artificial intelligence     power distribution control     state estimation    

Value Engineering/Value Management Model and Application of Aerospace Projects

Wan-hua Qiu,Han-peng Zhang,Ze-Shui Xu,De-Sheng Wu

《工程管理前沿(英文)》 2015年 第2卷 第4期   页码 373-377 doi: 10.15302/J-FEM-2015056

摘要: This paper presents a new space model developed by general value engineering/value management model. The authors take the function analysis, function optimization and function realization of the development object as the basic point, to get the final optimization structure by value evaluation, so as to improve the project quality and reduce the project cost. The final case shows that the application of this model can save about 18% of the time and considerable cost of the usually planned projects under the condition of quality assurance.

关键词: aerospace project     value engineering     value optimization     value stream     design structure matrix    

Higher heating value prediction of torrefaction char produced from non-woody biomass

Nitipong SOPONPONGPIPAT,Dussadeeporn SITTIKUL,Unchana SAE-UENG

《能源前沿(英文)》 2015年 第9卷 第4期   页码 461-471 doi: 10.1007/s11708-015-0377-3

摘要: The higher heating value of five types of non-woody biomass and their torrefaction char was predicted and compared with the experimental data obtained in this paper. The correlation proposed in this paper and the ones suggested by previous researches were used for prediction. For prediction using proximate analysis data, the mass fraction of fixed carbon and volatile matter had a strong effect on the higher heating value prediction of torrefaction char of non-woody biomass. The high ash fraction found in torrefied char resulted in a decrease in prediction accuracy. However, the prediction could be improved by taking into account the effect of ash fraction. The correlation developed in this paper gave a better prediction than the ones suggested by previous researches, and had an absolute average error (AAE) of 2.74% and an absolute bias error (ABE) of 0.52%. For prediction using elemental analysis data, the mass fraction of carbon, hydrogen, and oxygen had a strong effect on the higher heating value, while no relationship between the higher heating value and mass fractions of nitrogen and sulfur was discovered. The best correlation gave an AAE of 2.28% and an ABE of 1.36%.

关键词: higher heating value     correlation     biomass     proximate analysis     ultimate analysis    

Value and governance of high-speed railway

Xiaoyan LIN, Zehua ZHANG, Meng WANG

《工程管理前沿(英文)》 2017年 第4卷 第4期   页码 463-482 doi: 10.15302/J-FEM-2017054

摘要: This paper considers multiple perspectives to explore the concept of high-speed railway (HSR), rationally abstract its value formation mechanism, and quantitatively measure its actual performance. This paper analyzes the governance potential of major countries in the high-speed railway value chain and studies the feasible ways and development strategies to enhance the high-speed railway governance in China. Findings of this paper are as follows. First, the government, as the early manager of high-speed railway governance, has given way to Siemens and other integrated enterprises. Second, the high-speed railway standard output has become the core competitiveness that embodies high-speed railway. Third, the global high-speed railway market presents a hierarchical high-speed railway governance model and changes to a modular approach to governance.

关键词: high-speed railway value     communication value     high-speed railway value governance     governance path upgrade    

标题 作者 时间 类型 操作

Field investigation of intelligent compaction for hot mix asphalt resurfacing

Wei HU,Xiang SHU,Baoshan HUANG,Mark WOODS

期刊论文

Experimental research on compaction characteristics of aeolian sand

YUAN Yuqing, WANG Xuancang, ZHOU Xin

期刊论文

Numerical simulation of compaction parameters for sand-filled embankment using large thickness sand filling

Wentao WANG, Chongzhi TU, Rong LUO

期刊论文

Nonlinear sealing force of a seawater balance valve used in an 11000-meter manned submersible

期刊论文

高心墙堆石坝坝面碾压施工仿真理论与应用

钟登华,赵晨生,张平

期刊论文

Erratum to: Meter-scale variation within a single transect demands attention to taxon accumulation curves

期刊论文

A study on fatigue damage of asphalt mixture under different compaction using 3D-microstructural characteristics

Jing HU, Pengfei LIU, Bernhard STEINAUER

期刊论文

Experimental study on compaction-induced anisotropic mechanical property of rockfill material

Xiangtao ZHANG, Yizhao GAO, Yuan WANG, Yu-zhen YU, Xun SUN

期刊论文

板形计法的定义及实验应用

张进之,段春华,朱健勤

期刊论文

高碾压混凝土坝智能碾压理论研究

刘东海,李丙扬,崔博

期刊论文

水下多相流量计在深水油气田开发工程中的应用研究

刘太元,郭宏,郑利军

期刊论文

Intelligent algorithm for optimal meter placement and bus voltage estimation in ring main distribution

L. RAMESH, N. CHAKRABORTY, S. P. CHOWDHURY

期刊论文

Value Engineering/Value Management Model and Application of Aerospace Projects

Wan-hua Qiu,Han-peng Zhang,Ze-Shui Xu,De-Sheng Wu

期刊论文

Higher heating value prediction of torrefaction char produced from non-woody biomass

Nitipong SOPONPONGPIPAT,Dussadeeporn SITTIKUL,Unchana SAE-UENG

期刊论文

Value and governance of high-speed railway

Xiaoyan LIN, Zehua ZHANG, Meng WANG

期刊论文