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抗浮安全；隧道施工期；隧道运营期；覆土厚度 1

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Evaluating effect of chloride attack and concrete cover on the probability of corrosion

Sanjeev Kumar VERMA, Sudhir Singh BHADAURIA, Saleem AKHTAR

《结构与土木工程前沿（英文）》 2013年第7卷第4期页码 379-390 doi: 10.1007/s11709-013-0223-9

摘要： Corrosion of reinforced concrete (RC) structures is one of the significant causes of deterioration of reinforced concrete (RC) structures. Chlorination is a major process governing the initiation and advancement of the injurious corrosion of steel bars. Now, several researches on the chlorination of concrete structures have been ongoing around the world. Present article reviews several recently performed chlorination studies, and from results of a field survey evaluates the effect of chloride content on the probability of corrosion and the influence of concrete compressive strength on the chloride content and penetration, also evaluates the effect of concrete cover over the chloride content of the RC structures at rebar depth and on the probability of corrosion.

关键词： concrete chloride reinforcement corrosion deterioration cover

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Independent cover meshless particle method for complex geotechnical engineering

Jianqiu WU, Yongchang CAI

《结构与土木工程前沿（英文）》 2018年第12卷第4期页码 515-526 doi: 10.1007/s11709-017-0428-4

摘要： A new Independent Cover Meshless Particle (ICMP) method is proposed for the analysis of complex geotechnical engineering. In the ICMP method, the independent rectangular cover regardless of the shape of the analysis model is employed as the influence domain of each discrete node, the general polynomial is employed as the meshless interpolation function of the independent nodal cover, and the Cartesian Transformation Method (CTM) is used for the numerical integration of the nodal covers cut by material interfaces, joints, cracks and faults. The present method has a simple formulation and a low computational cost, and is easy for the numerical analysis and modeling of complex geotechnical engineering. Several typical numerical examples are presented to demonstrate the accuracy and robustness of the proposed method.

关键词： meshless method particle method independent cover CTM geotechnical engineering

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Industrial development and land use/cover change and their effects on local environment: a case study

Yurui LI, Hualou LONG, Yansui LIU

《环境科学与工程前沿（英文）》 2010年第4卷第4期页码 438-448 doi: 10.1007/s11783-010-0273-3

摘要： The interactions among industrial development, land use/cover change (LUCC), and environmental effects in Changshu in the eastern coastal China were analyzed using high-resolution Landsat TM data in 1990, 1995, 2000, and 2006, socio-economic data and water environmental quality monitoring data from research institutes and governmental departments. Three phases of industrial development in Changshu were examined (i.e., the three periods of 1990 to 1995, 1995 to 2000, and 2000 to 2006). Besides industrial development and rapid urbanization, land use/cover in Changshu had changed drastically from 1990 to 2006. This change was characterized by major replacements of farmland by urban and rural settlements, artificial ponds, forested and constructed land. Industrialization, urbanization, agricultural structure adjustment, and rural housing construction were the major socio-economic driving forces of LUCC in Changshu. In addition, the annual value of ecosystem services in Changshu decreased slightly during 1990–2000, but increased significantly during 2000–2006. Nevertheless, the local environmental quality in Changshu, especially in rural areas, has not yet been improved significantly. Thus, this paper suggests an increased attention to fully realize the role of land supply in adjustment of environment-friendly industrial structure and urban-rural spatial restructuring, and translating the land management and environmental protection policies into an optimized industrial distribution and land-use pattern.

关键词： industrial development land use/cover change (LUCC) driving forces environmental effects ecosystem services value (ESV) water environmental quality Changshu

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Effect of land use and land cover change on soil erosion and the spatio-temporal variation in Liupan

Bin QUAN, M. J. M. R?MKENS, Rui LI, Fang WANG, Jie CHEN

《环境科学与工程前沿（英文）》 2011年第5卷第4期页码 564-572 doi: 10.1007/s11783-011-0348-9

摘要： The Liupan Mountains are located in the southern Ningxia Hui Autonomous Region of China, that forms an important divide between landforms and bio-geographic regions. The populated part of the Liupan Mountain Region has suffered tremendous ecological damage over time due to population pressure, excessive demand and inappropriate use of agricultural land resources. To present the relationship between land use/cover change and spatio-temporal variation of soil erosion, data sets of land use between the late 1980s and 2000 were obtained from Landsat Thematic Mapper (TM) imagery, and spatial models were used to characterize landscape and soil erosion conditions. Also, soil erosion in response to land use and land cover change were quantified and analyzed using data from geographical information systems and remote sensing. Soil erosion by water was the dominant mode of soil loss, while soil erosion by wind was only present on a relatively small area. The degree of soil erosion was classified into five severity classes: slight, light, moderate, severe, and very severe. Soil erosion in the Liupan Mountain Region increased between the late 1980s and 2000, both in terms of acreage and severity. Moderate, severe, and very severe eroded areas accounted for 54.86% of the total land area. The lightly eroded area decreased, while the moderately eroded area increased by 368817 ha (22%) followed by severe erosion with 146552 ha (8.8%), and very severe erosion by 97067.6 ha (5.8%). Soil loss on sloping cropland increased with slope gradients. About 90% of the cropland was located on slopes less than 15°. Most of the increase in soil erosion on cropland was due to conversion of steep slopes to cropland and degradation of grassland and increased activities. Soil erosion was severe on grassland with a moderate or low grass cover and on dry land. Human activities, cultivation on steep slopes, and overgrazing of pastures were the main reasons for the increase in erosion severity.

关键词： land use/land cover change soil erosion geographical information system remote sensing Liupan Mountain Region

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基于抗浮稳定的盾构隧道合理覆土厚度研究

刘学彦,袁大军,姜曦

《中国工程科学》 2015年第17卷第1期页码 88-95

摘要：

运用理论分析和数值计算相结合的方法，分别从施工期和运营期角度提出了隧道抗浮稳定合理覆土厚度设定原则和理论计算方法；对于隧道施工期，考虑土体侧向摩阻力和管片环间摩阻力的影响等较为有利因素，同时考虑未凝浆液的影响等不利因素，建立了合理覆土厚度的理论计算公式；对于隧道运营期，建议只考虑隧道上覆土体自重进行抗浮，对于存在洪水冲刷的隧道设计，其上覆土体厚度还要加上设计冲刷深度；为南京某在建隧道的纵断面设计提供了一定的参考，同时也为其他过江海盾构隧道满足抗浮稳定的覆土厚度设定提供理论支持。

关键词：抗浮安全；隧道施工期；隧道运营期；覆土厚度

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Land use/cover change effects on floods with different return periods: a case study of Beijing, China

Yueling WANG, Xiaoliu YANG

《环境科学与工程前沿（英文）》 2013年第7卷第5期页码 769-776 doi: 10.1007/s11783-013-0542-z

摘要： In this study, an approach integrating digital land use/cover change (LUCC) analysis, hydraulic modeling and statistical methods was applied to quantify the effect of LUCC on floods in terms of inundation extent, flood arrival time and maximum water depth. The study took Beijing as an example and analyzed five specific floods with return periods of 20-year, 50-year, 100-year, 1000-year and 10000-year on the basis of LUCC over a nine-year period from 1996 to 2004. The analysis reveals that 1) during the period of analysis Beijing experienced unprecedented LUCC; 2) LUCC can affect inundation extent and flood arrival time, and floods with longer return periods are more influenced; 3) LUCC can affect maximum water depth and floods with shorter return periods are more influenced; and 4) LUCC is a major flood security stressor for Beijing. It warns that those cities having experienced rapid expansion during recent decades in China are in danger of more serious floods and recommends that their actual land use patterns should be carefully assessed considering flood security. This integrated approach is demonstrated to be a useful tool for joint assessment, planning and management of land and water.

关键词： inundation extent flood arrival time maximum water depth shallow flow model

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Interaction and independence on methane oxidation of landfill cover soil among three impact factors:

Pinjing HE, Na YANG, Wenjuan FANG, Fan Lü, Liming SHAO

《环境科学与工程前沿（英文）》 2011年第5卷第2期页码 175-185 doi: 10.1007/s11783-011-0320-8

摘要： To understand the influence patterns and interactions of three important environmental factors, i.e. soil water content, oxygen concentration, and ammonium addition, on methane oxidation, the soils from landfill cover layers were incubated under full factorial parameter settings. In addition to the methane oxidation rate, the quantities and community structures of methanotrophs were analyzed to determine the methane oxidation capacity of the soils. Canonical correspondence analysis was utilized to distinguish the important impact factors. Water content was found to be the most important factor influencing the methane oxidation rate and Type II methanotrophs, and the optimum value was 15% (w/w), which induced methane oxidation rates 10- and 6- times greater than those observed at 5% (w/w) and 20% (w/w), respectively. Ambient oxygen conditions were more suitable for methane oxidation than 3% oxygen. The addition of of ammonium induced different effects on methane oxidation capacity when conducted at low or high water content. With regard to the methanotrophs, Type II was sensitive to the changes of water content, while Type I was influenced by oxygen content. Furthermore, the methanotrophic acidophile, , was detected in soils with a pH of 4.9, which extended their known living environments.

关键词： quantitative polymerase chain reaction (PCR) denaturing gradient gel electrophoresis (DGGE) principal component analysis (PCA) canonical correspondence analysis (CCA)

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盾构法修建水下隧道的关键技术问题

孙谋,谭忠盛

《中国工程科学》 2009年第11卷第7期页码 18-23

摘要：

结合武汉长江隧道等水下盾构隧道工程，对水下盾构施工合理覆盖层厚度、盾构类型及关键参数确定进行了分析。对水下盾构施工关键技术如开挖面稳定技术、预防泥水喷发技术、防止隧道上浮技术、盾构姿态控制技术、长距离掘进及盾构水中对接技术、盾构始发与到达技术等进行了归纳。

关键词：水下隧道盾构法覆盖层厚度盾构选型关键技术

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Experimental study on slender buckling-restrained knee braces with round steel bar cores

《结构与土木工程前沿（英文）》 2023年第17卷第1期页码 99-121 doi: 10.1007/s11709-022-0875-4

摘要： This study aimed to investigate a novel slender buckling-restrained knee brace damper (BRKB) for welded and weld-free steel framing systems. The proposed BRKB adopts steel bar cores connected by a central coupler and restrained by tube buckling restrainers with a cover tube supporter. The advantages of the proposed damper include easy assembly compared to conventional buckling restrained braces, and high architectural flexibility for the retrofitting of large-span weld-free or welded steel moment-resisting systems. Specifically, by increasing the number of contraction allowances, undesirable failure mechanisms that are global instability and local buckling of the restrainer ends can be effectively suppressed because the more uniform plastic deformation of the core bar can be achieved longitudinally. In this study, displacement-controlled compression and cyclic loading tests were carried out to investigate the deformation capacities of the proposed BRKBs. Structural performance metrics associated with both loading tests, such as strength capacities, strains at the cover tubes and buckling restrainers, and hysteretic behaviors of the proposed damper under cyclic loads, were measured and discussed. Test results revealed that the geometrical characteristics of the cover tubes and adopted contraction allowances at the dampers play essential roles in their load-bearing capacities.

关键词： weld-free beam-to-column connections moment-resisting frame cyclic and compression loading tests buckling-restrained knee brace cover tube