检索结果-南通市图书馆

山东大学学报（理学版） 2024年第6期59卷 122-126页

作者：高玉峰冯德成甘肃省白银市第十中学甘肃白银730900 西北师范大学数学与统计学院甘肃兰州730070

利用条件弱鞅和条件N-弱鞅的性质,得到条件弱鞅的上穿不等式和条件N-弱鞅的下穿不等式,推广已有文献中的相关结果。

关键词：条件弱鞅条件N-弱鞅上穿不等式下穿不等式

面向城市更新的外附子结构式既有建筑抗震性能提升技术研究进展

在线全文

学校读者我要写书评

暂无评论

建筑结构 2024年第19期54卷 21-34页

作者：吴刚曹徐阳冯德成东南大学土木工程学院河海大学土木与交通学院

外附子结构加固技术作为一种提升既有建筑整体抗震性能的有效方法，通过将子结构与既有结构外附连接为一个整体，使得新-旧结构体系在地震作用下协同工作，有效改善既有结构的传力机制，定向转移既有结构的损伤累积，显著提升整体体系... 详细信息

外附子结构加固技术作为一种提升既有建筑整体抗震性能的有效方法，通过将子结构与既有结构外附连接为一个整体，使得新-旧结构体系在地震作用下协同工作，有效改善既有结构的传力机制，定向转移既有结构的损伤累积，显著提升整体体系的力学性能。此外，由于外附子结构加固技术为外部作业，不影响内部结构的正常使用，可实现无干扰加固的需求，更加符合“城市更新”的发展模式。近几十年来外附子结构加固技术在世界范围内得到了广泛应用。针对外附子结构加固技术的发展现状，开展了其提升既有建筑抗震性能的进展研究，首先介绍了外附子结构加固技术的总体概念(原理、优势),其次介绍了典型外附子结构的加固形式(框架、框架-支撑、墙体类型),最后总结了外附子结构加固技术的关键问题(界面剪切传递机制、节点连接性能、预制-装配技术的结合、环境交互和维护成本)。结果表明外附子结构加固技术在未来数年内依旧具备广阔前景。

关键词：外附子结构城市更新抗震加固抗震性能韧性提升

Multi-Scale Damage Model for Quasi-Brittle Composite Materials

在线全文

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2020年第3期122卷 997-1014页

作者： decheng feng Key Laboratory of Concrete and Prestressed Concrete Structures of the Ministry of Education Southeast UniversityNanjing211189China. The Jiangsu Institution of Engineers Nanjing210019China.

In the present paper,a hierarchical multi-scale method is developed for the nonlinear analysis of composite materials undergoing heterogeneity and *** from the homogenization theory,the energy equivalence between scales is *** accompanied with the energy based damage model,the multi-scale damage evolutions are resolved by homogenizing the energy scalar over the *** macroscopic behaviors described by the multi-scale damage evolutions represent the mesoscopic heterogeneity and damage of the composites.A rather simple structure made from particle reinforced composite materials is developed as a numerical *** agreement between the fullscale simulating results and the multi-scale simulating results demonstrates the capacity of the proposed model to simulate nonlinear behaviors of quasi-brittle composite materials within the multi-scale framework.

关键词： Energy integration multi-scale damage evolution nonlinearity composites quasi-brittle materials

Field monitoring of differential frost heave in widened highway subgrade

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Research in Cold and Arid Regions 2021年第5期13卷 408-418页

作者： Xufeng Lu feng Zhang KangWei Tang decheng feng School of Transportation Science and Engineering Harbin Institute of TechnologyHeilongjiang 150090HarbinChina

In cold regions,the widened subgrade could produce uneven frost heave that is detrimental to the *** study investigates the differential frost heave characteristics in a widened *** field monitoring system mainly consists of temperature,moisture,and displacement sensors and distributed optical fiber cables for strain *** monitoring results show that the cooling period in the subgrade is longer than the warming *** content in the subgrade changes significantly within 0−2 m below the subgrade surface but stabilizes within 2−5 *** maximum frost heave occurs from February to *** comparison,the existing subgrade has a longer freezing period and larger heave value,caused by the higher density and water content *** in the existing subgrade migrates into the new one after widening,leading to frost heave reduction in the existing ***,the traffic loads result in the consolidation of the new subgrade,thus reducing the heave value in the second *** the third year,the water supply from the existing subgrade facilitates the frost heave in the new *** tensile strain distributions obtained by the distributed optical fiber cables show that the maximum differential frost heave occurs at the joint between the existing and new *** differential frost heave gradually stabilizes after three ***,an improved frost heave prediction model is developed based on the segregation potential concept and monitoring results.

关键词： widened subgrade differential frost heave field monitoring distributed optical fiber strain sensing seasonally frozen region

Recent developments in asphalt-aggregate separation technology for reclaimed asphalt pavement

在线全文

学校读者我要写书评

暂无评论

Journal of Road Engineering 2022年第4期2卷 332-347页

作者： decheng feng Jiwei Cao Libo Gao Junyan Yi School of Transportation Science and Engineering Harbin Institute of TechnologyHarbin 150090China Liaoning Provincial Transportation Investment Group Co. Ltd.Shenyang 110166China Liaoning Transportation Research Institute Co. Ltd.Shenyang 110000China

Reclaimed asphalt pavement(RAP)has significant recycling value because it contains nonrenewable resources including asphalt and ***,thus far,only a small part of RAP materials can be used in the con-struction of recycled asphalt pavement,and the usage is regarded as a low-value utilization in the underlying *** of the most important reasons for this shortcoming is the problem of false particle size and pseudo gradation of RAP ***,identifying suitable asphalt-aggregate separation technology is essential for improving the utilization of RAP materials in recycled asphalt mixture and enhancing the construction quality of recycled asphalt *** address this,the paper performed a systematic review of asphalt-aggregate separation technologies for processing RAP materials and their ***,based on the composition of the asphalt mixture and the characteristics of RAP materials after aging,the key RAP separation technologies were ***,the concept,principle,and implementation methods of physical,chemical,and biological sep-aration methods of RAP materials were comprehensively ***,the advantages and disadvantages of various separation technologies were discussed by comparing them with the related technologies in the petrochemical *** application prospects of various asphalt-aggregate separation methods for RAP materials can provide a reference for upgrading and expanding solid waste recycling technology for asphalt pavement.

关键词： Road engineering Reclaimed asphalt pavement Asphalt-aggregate separation Physical separation Chemical separation Biological separation

Numerical simulation of electroosmosis in unsaturated compacted clay

在线全文

学校读者我要写书评

暂无评论

Research in Cold and Arid Regions 2021年第5期13卷 394-407页

作者： KangWei Tang feng Zhang decheng feng GuanFu Wang School of Transportation Science and Engineering Harbin Institute of Technology73 Huanghe RoadHarbinHeilongjiang 150090China

The moisture content of a road subgrade in cold regions will increase after freeze-thaw cycles,resulting in subgrade strength and stiffness *** is widely used in treating saturated soft soils to decrease the moisture *** induced moisture migration during electroosmosis in unsaturated soil is much more complex than that of saturated soil because of a series of nonlinear changes in soil *** study first uses an exponential function to characterize the relationship between electroosmotic permeability and saturation ***,a one-dimensional model is developed to simulate the electroosmosis-induced moisture migration in unsaturated *** results show that electroosmosis reduces the saturation degree of the unsaturated soil,indicating that it can be applied to subgrade *** parameters such as soil pore size distribution coefficient,air entry value,and effective voltage significantly affect moisture *** properties of unsaturated soils are extremely important to the efficiency of electroosmosis.

关键词： electro-osmosis unsaturated clay moisture migration numerical simulation

A nonlinear interface structural damage model between ice crystal and frozen clay soil

在线全文

学校读者我要写书评

暂无评论

Research in Cold and Arid Regions 2021年第2期13卷 150-166页

作者： Sheng Shi feng Zhang KangWei Tang decheng feng Xufeng Lu School of Transportation Science and Engineering Harbin Institute of TechnologyHeilongjiangHarbin 150090China State Key Laboratory of Road Engineering Safety and Health in Cold and High−Altitude Regions CCCC First Highway Consultants Co.Ltd.Xi'an 710075China

The shear properties of ice-frozen soil interface are important when studying the constitutive model of frozen soil and slope stability in cold regions. In this research, a series of cryogenic direct shear tests for ice-frozen clay soil interface were conducted. Based on experimental results, a nonlinear interface structural damage model is proposed to describe the shear properties of ice-frozen clay soil interface. Firstly, the cementation and friction structural properties of frozen soil materials were analyzed, and a structural parameter of the ice-frozen clay soil interface is proposed based on the cryogenic direct shear test results. Secondly, a structural coefficient ratio is proposed to describe the structural development degree of ice-frozen clay soil interface under load, which is able to normalize the shear stress of ice-frozen clay soil interface,and the normalized data can be described by the Duncan-Chang model. Finally, the tangent stiffness of ice-frozen clay soil interface is calculated, which can be applied to the mechanics analysis of frozen soil. Also, the shear stress of ice-frozen clay soil interface calculated by the proposed model is compared with test results.

关键词： ice-frozen clay soil interface cryogenic direct shear test structural coefficient ratio shear tangent stiffness cementation

Nanoparticles-modified polymer-based solar-reflective coating as a cooling overlay for asphalt pavement

在线全文

学校读者我要写书评

暂无评论

International Journal of Smart and Nano Materials 2013年第2期4卷 102-111页

作者： He Wang Jing Zhong decheng feng Jing Meng Ning Xie School of Transportation Science and Engineering Harbin Institute of TechnologyHarbin 150001China School of Civil Engineering Harbin Institute of TechnologyHarbin 150001China

The phenomenon of rutting is one of the most serious problems on asphalt *** the surface temperature of the asphalt pavement is an effective method to solve the rutting problem on asphalt *** this study,a nano-sized-particlesfilled polymer composite was developed as an overlay to reflect solar energy and decrease the surface temperature of asphalt *** overlay was composed of acrylic or epoxy resin filled with nano TiO_(2) or nano TiNO_(2).The solar reflection of the nanoparticle-filled polymers was tested,and the results showed that solar reflection effectiveness of the TiO_(2)/acrylic composite reached the highest *** results of outdoor temperature tests indicate that the solar-reflective overlay could decrease the surface temperature of asphalt pavements by about 10℃ when the pavement temperature is about 60℃.

关键词： solar reflective nanoparticles polymer overlay asphalt pavement

Investigation on the properties of compacted silty clay subjected to electro-osmosis using bender element

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Research in Cold and Arid Regions 2023年第6期15卷 253-261页

作者： KangWei Tang Chuang Lin Hao Wang WeiJun Qin decheng feng feng Zhang School of Transportation Science and Engineering Harbin Institute of Technology73 Huanghe RoadHarbinHeilongjiang 150090China Laboratoire Navier/CERMES Ecole des Ponts ParisTech6 et 8 Avenue Blaise PascalCite DescartesChamps-sur-Marne77455 Marne La Vallee Cedex 2France Key Laboratory of Transportation Industry for Highway Construction and Maintenance Technology in Seasonal Frozen Soil Areas(Changchun) 4887 Xinglong RoadChangchunJinlin 130102China

The moisture content of subgrade soil in seasonally frozen regions is often higher than its optimum value,leading to a decline in mechanical properties and a reduction in subgrade bearing ***-osmosis has shown promise as a technology for controlling subgrade moisture,but significant heterogeneity has also been observed in treated *** study investigates the impact of electro-osmosis on soil stiffness through a series of bender element tests of compacted *** effects of dry density and supply voltage on the performance of electroosmosis treatment and the layered structure and anisotropy of the soil were *** results show that electro-osmosis treatment increased the shear wave velocity of the soil by 140% compared to untreated saturated soil and by 70% compared to soil with optimum water *** has also been found that layered compaction of soil resulted in a layered structure,with electro-osmosis having a more prominent impact on soil near the cathode,resulting in a more pronounced layered ***,electro-osmosis was found to enhance soil anisotropy,particularly near the *** the dry density and voltage levels can help improve soil *** findings provide insights into the potential use of electro-osmosis in improving soil stiffness,which could benefit various engineering applications.

关键词： Subgrade soil Electro-osmosis Bender element Layered structure Anisotropy

Determination of allowable subgrade frost heave with the pavement roughness index in numerical analysis

在线全文

学校读者我要写书评

暂无评论

Research in Cold and Arid Regions 2015年第5期7卷 587-593页

作者： HongYan Ma feng Zhang decheng feng Bo Lin School of Transportation Science and Engineering Harbin Institute of Technology

Frost heave is an upward swelling of soil during cryogenic conditions in cold regions. It is caused by the accumulation of ice crystals in subgrade soil, which grow upwards when freezing temperatures penetrate into the subgrade. This study establishes the allowable soil subgrade frost heave based on the roughness standard of asphalt pavement in China, and aims to balance the pavement design and frost heave resistance of subgrades in cold regions. We formulated a mechanical model of pavement supported by the boundary conditions of differential frost heave, based on the elastie layered system theory. The differential soil subgrade frost heave was modeled as a sinusoidal function, and the allowable frost heave and the roughness index were modeled as the displacement boundaries for the top and bottom of the pavement structure. Then the allowable frost heave was back-calculated according to the roughness standard. Numerical results show that the allowable frost heave depends on the pavement structure, material properties, the highway grade, and other factors. In order to ensure that the actual soil subgrade frost heave is lower than the allowable frost heave, pavement structures and materials need to be selected and designed carefully. The numerical method proposed here can be applied to establish the frost heave re- sistance of subgrade when the pavement structure and materials are determined.

关键词： differential frost heave asphalt pavement elastic layered system theory roughness index allowable frost heave