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Towards safe and comfortable high-speed transportation infrastructure

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2012年第11期13卷 799-801页

作者： ren-peng chen Xiong (Bill) YU MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering Department of Civil EngineeringZhejiang UniversityHangzhou 310058China Department of Civil Engineering Case Western Reserve UniversityClevelandOhio 44106USA

In the past decades,we have witnessed the rapid development of high-speed transportation infrastructure,such as high-speed railways,urban subways,expressways,and airfields *** a major effort in transportation infrastructure development,China plans to build 20 000 km of high-speed rail network by the year of 2020 with design speed up to 500 km/*** such a fast pace,ensuring the safe and comfortable high-speed transportation presents major technical challenges to the design,construction,and maintenance of high performance infrastructure.

关键词：交通基础设施建设舒适安全高速铁路城市地铁高速公路交通运输铁路网络

Effect of seepage on soil arching effect in deep shield tunnel

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Underground Space 2023年第5期12卷 218-233页

作者： Xu Song Fan-Yan Meng ren-peng chen Han-Lin Wang Huai-Na Wu Research Center for Advanced Underground Space Technologies of Hunan University Changsha 410082China Key Laboratory of Building Safety and Energy Efficiency of the Ministry of Education Hunan UniversityChangsha 410082China College of Civil Engineering Hunan UniversityChangsha 410082China

Shield tunneling and post-tunneling steady seepage are accompanied by stress and displacement variations,which could induce and influence the soil arching *** there are many studies on the tunneling-induced soil arching effect,the research about the effect of seepage on soil arching effect is extremely *** this study,a numerical model is firstly established and verified by field ***,a series of numerical models,whose simulation method of steady seepage is verified by adopting the conformal mapping technique,are established to study the soil arching evolution of deep-buried tunneling and post-construction steady *** results indicate that seepage leads to an increase in effective vertical stress,which is consistent with the existing *** seepage weakens the soil arching effect resulting in the height of the arch zone reducing from 2.38D(D is the tunnel diameter)to *** seepage leads to the further development of ground consolidation settlement,but the differential displacement in the soil mass *** ground reaction curve in the steady seepage condition shows a bigger value than that after *** is reasonable to control the ground loss ratio in the range of 0.5–1.0%,which can minimize overburden pressure with moderate ground deformation.

关键词： Soil arching effect Steady seepage Numerical simulation Deep shield tunnel Stress change

Investigation of migration of pollutant at the base of Suzhou Qizishan landfill without a liner system

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第3期10卷 439-449页

作者： Hai-jian XIE Yun-min chen Liang-tong ZHAN ren-peng chen Xiao-wu TANG Ru-hai chen Han KE MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering Zhejiang University Hangzhou 310058 China College of Civil Engineering and Architeeture Zhejiang University Hangzhou 310058 China

We investigated migration of pollutant at the base of the Suzhou landfill after it had been operated for 13 years. The investigation was carried out by performing chemical analyses on the soil samples taken from the silty clay deposit. Concentrations of chloride, chemical oxygen demand （COD） and the heavy metals in the soil samples were determined using the standard methods. The experimental data showed that the maximum migration depth of chloride was more than 10 m, while the maximum migration depth of COD varied between 1 and 3.5 m. It is believed that the difference is attributed to the variation in diffusion rate and leachate-soil interaction. The chloride profiles also indicated that adveetion may be the dominant contaminant transport mechanism at this site. The total contents ofCu, Pb and Cr are very close to the background levels and the concentration values of these metals mainly are lower than the threshold values specified by the Chinese soil quality standard and the European one. The water-extractable concentrations of COD in the surface of the silty clay generally exceed the limit value specified by the Chinese standard. The concentrations of copper and chromium in pore water are 1-2 orders of magnitude less than the total concentrations of these heavy metals within the soils, implying that heavy metals are mainly adsorbed by the soil particles. Finally, remediation methods were suggested for this landfill site.

关键词： Uncontrolled landfill Field investigation Contaminant migration Soil contamination Heavy metals Organic contaminants Chloride

A semi-analytical method for the analysis of pile-supported embankments

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2012年第11期13卷 888-894页

作者： Wan-huan ZHOU ren-peng chen Lin-shuang ZHAO Zheng-zhong XU Yun-min chen Department of Civil and Environmental Engineering University of Macao Macao China MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering Department of Civil Engineering Zhejiang University Hangzhou 310058 China

In this paper,a semi-analytical method for the analysis of pile-supported embankments is *** mathematic model describes the cooperative behavior of pile,pile cap,foundation soil,and embankment *** on Terzaghi's 1D consolidation theory of saturated soil,the consolidation of foundation soil is *** embankments with two different types of piles:floating piles and end-bearing piles are investigated and *** results of axial force and skin friction distributions along the pile and the settlements of pile-supported embankments are *** is found that it takes a longer time for soil consolidation in the embankment with floating piles,compared with the case using end-bearing *** differential settlement between the pile and surrounding soil at the pile top is larger for the embankment with end-bearing piles,compared with the case of floating piles.

关键词： Pile-supported embankment Soil arching Load transfer Equal settlement plane Soft soils

Weakening behavior of waterproof performance in joints of shield tunnels under adjacent constructions

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结构与土木工程前沿:英文版 2023年第6期17卷 884-900页

作者： Huai-Na WU Lei LIU Yuan LIU ren-peng chen Hai-Lin WANG Shi-Qiang RUAN Meng FAN Research Center of Underground Space Advanced Technology Hunan UniversityChangsha410082China Key Laboratory of Building Safety and Energy Efficiency of the Ministry of Education Hunan UniversityChangsha410082China Department of Civil Engineering Hunan UniversityChangsha410082China Hunan Provincial Communications Planning Survey&Design Institute Co.Ltd.Changsha410082China

Groundwater leakage in shield tunnels poses a threat to the safety and durability of tunnel structures. Disturbance of adjacent constructions during the operation of shield tunnels frequently occurs in China, leading to deformation of tunnel lining and leakage in joints. Understanding the impact of adjacent constructions on the waterproofing performance of the lining is critical for the protection of shield tunnels. In this study, the weakening behavior of waterproof performance was investigated in the joints of shield tunnels under transverse deformation induced by adjacent construction. First, the relationship between the joint opening and transverse deformation under three typical adjacent constructions (upper loading, upper excavation, and side excavation) was investigated via elaborate numerical simulations. Subsequently, the evolution of the waterproof performance of a common gasket with a joint opening was examined by establishing a coupled Eulerian-Lagrangian model of joint seepage, and a formula describing the relationship between waterproof performance and joint opening was proposed. Finally, the weakening law of waterproofing performance was investigated based on the results of the aforementioned studies. It was determined that the joints with the greatest decline in waterproof performance were located at the tunnel shoulder in the upper loading case, tunnel crown in the upper excavation case, and tunnel shoulder in the side excavation case. When the waterproof performance of these joints decreased to 50% and 30%, the transverse deformations were 60 and 90 mm under upper loading, 90 and 140 mm under upper excavation, and 45 and 70 mm under side excavation, respectively. The results provide a straightforward reference for setting a controlled deformation standard considering the waterproof performance.

关键词： shield tunnel waterproof performance horizontal transverse deformation joint opening weakenning behavior

The environment,especially the minimum temperature,affects summer maize grain yield by regulating ear differentiation and grain development

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Journal of Integrative Agriculture 2024年第7期23卷 2227-2241页

作者： Jing chen Baizhao ren Bin Zhao peng Liu Jiwang Zhang State Key Laboratory of Crop Biology/College of Agronomy Shandong Agricultural UniversityTai’an 271018

Ear differentiation,grain development and their interaction with factors in the growing environment,such as temperature,solar radiation and precipitation,greatly influence grain number and grain weight,and ultimately affect summer maize *** this study,field experiments involving different sowing dates were conducted over three years to evaluate the effects of temperature factors,average solar radiation and total precipitation on the growth process,ear differentiation,fertilization characteristics,grain filling and yield of summer maize varieties with different growth *** hybrids were evaluated in Huang-Huai-Hai Plain(HHHP),China from 2018 to 2020 with five different sowing *** results showed that the grain yield formation of summer maize was strongly impacted by the environment from the silking(R1)to milking(R3)*** minimum temperature(AT_(min))was the key environmental factor that determined *** in the length of the growing season(r=–0.556,Prentiation and grain development at the pre-and post-silking stages improved maize yie

关键词： sowing date hybrid maturity growing environment ear differentiation and grain development

A Novel Graph Structure Learning Based Semi-Supervised Framework for Anomaly Identification in Fluctuating IoT Environment

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Computer Modeling in Engineering & Sciences 2024年第9期140卷 3001-3016页

作者： Weijian Song Xi Li peng chen Juan chen Jianhua ren Yunni Xia School of Computer and Software Engineering Xihua UniversityChengdu610039China West China Second University Hospital Sichuan UniversityChengdu610065China School of Computer Science Chongqing UniversityChongqing400044China

With the rapid development of Internet of Things(IoT)technology,IoT systems have been widely applied in health-care,transportation,home,and other ***,with the continuous expansion of the scale and increasing complexity of IoT systems,the stability and security issues of IoT systems have become increasingly ***,it is crucial to detect anomalies in the collected IoT time series from various ***,deep learning models have been leveraged for IoT anomaly ***,owing to the challenges associated with data labeling,most IoT anomaly detection methods resort to unsupervised learning ***,the absence of accurate abnormal information in unsupervised learning methods limits their *** address these problems,we propose AS-GCN-MTM,an adaptive structural Graph Convolutional Networks(GCN)-based framework using a mean-teacher mechanism(AS-GCN-MTM)for anomaly *** performs better than unsupervised methods using only a small amount of labeled *** Teachers is an effective semi-supervised learning method that utilizes unlabeled data for training to improve the generalization ability and performance of the ***,the dependencies between data are often unknown in time series *** solve this problem,we designed a graph structure adaptive learning layer based on neural networks,which can automatically learn the graph structure from time series *** not only better captures the relationships between nodes but also enhances the model’s performance by augmenting key *** have demonstrated that our method improves the baseline model with the highest F1 value by 10.4%,36.1%,and 5.6%,respectively,on three real datasets with a 10%data labeling rate.

关键词： IoT multivariate time series anomaly detection graph learning semi-supervised mean teachers

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高铁路基近期研究(英文)

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2014年第12期15卷 1034-1038页

作者： ren-peng chen Jin-miao chen Han-lin WANG Department of Civil Engineering Zhejiang University

随着高速铁路的快速发展,高铁路基的研究成为一大热点。目前大量的研究工作集中在高铁路基动力响应、工后沉降和长期服役性能。这些工作促进了对高铁路基一般规律的了解,但距准确评价路基在百年服役过程中经受干湿循环、温度变化与动荷... 详细信息

随着高速铁路的快速发展,高铁路基的研究成为一大热点。目前大量的研究工作集中在高铁路基动力响应、工后沉降和长期服役性能。这些工作促进了对高铁路基一般规律的了解,但距准确评价路基在百年服役过程中经受干湿循环、温度变化与动荷载耦合作用下服役性能的改变尚远。本文总结了高铁路基近期的研究成果,并提出了未来的研究方向。

关键词：高铁路基:动力响应工后沉降长期服役性能

Influence of erbium addition on microstructure and performances of AlSi10Mg alloy prepared by selective laser melting

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Journal of Rare Earths 2024年第10期42卷 1988-1994页

作者： Bin chen Fuzhu Wang Shiming ren peng Xia Zhipeng Wang Jianfei Hao Zhiping chen Runxia Li Hongxiang Jiang Research Institute of Interdisciplinary Science & School of Materials Science and Engineering Dongguan University of Technology College of Materials Science and Engineering Shenzhen University Shi-Changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of Sciences School of Materials Science and Engineering University of Science and Technology of China

The effect of rare earth addition on the microstructure and mechanical performances of as-cast and wrought Al alloys has been attracting increasing attention *** earth addition has great potential in modifying the structure and improving the properties of ***,there are currently few reports about the effect of rare earth addition on the microstructure and performances of Al alloys prepared via selective laser ***,AlSi10Mg alloys were manufactured using selective laser melting,and the effect of Er addition was *** results indicate that Er addition leads toα-Al refinement and modifies the minority Si *** formation of the Al3Er phase induced by Er addition enhances the stren gth of the *** of the Si phase also increases *** strategy can help improve the mechanical performance of alum inum alloys prepared via selective laser melting.

关键词： Aluminum alloy Er Microstructure Rare earths Selective laser melting Tensile performance