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Interaction Mechanism of the Frost Heaving of the Filler and Skeleton Particles in a Micro-Frost-Heaving Filling Material
Xiaoyan Du,
Yangsheng Ye,
Qianli Zhang,
Degou Cai
Issue:
Volume 6, Issue 4, July 2018
Pages:
109-117
Received:
10 June 2018
Accepted:
16 July 2018
Published:
14 September 2018
Abstract: To address the adverse effects of the frost heaving of subgrades in regions with seasonal frozen soil on the smoothness of high-speed railway tracks, the effects of several factors—including filler, water content and external loading—on a micro-frost-heaving (MFH) filling material were studied through laboratory experiments and theoretical analysis. In addition, the interaction mechanism between the filler and skeleton particles during the frost heaving process was analyzed. The results show the following: The MFH filling material was composed of a coarse-grained skeleton, a filler between skeleton particles and the remaining unfilled voids. When the filling ratio of the filler was 0.25, the filling material underwent initial macroscopic frost heaving. An overlying load could inhibit the filling material from frost heaving. During the frost heaving process, the volume of coarse skeleton particles with high stiffness remained almost unchanged, whereas the filler expanded in volume and thus filled the remaining voids between skeleton particles and lifted the skeleton particles, resulting in macroscopic frost heaving of the filling material. When their ratio was relatively high, the remaining voids between skeleton particles had a strong absorptivity and weakened the capacity of the filler to lift the skeleton particles. The filler raised the skeleton particles, resulting in an increase in the gaps between them, which in turn facilitated the filling action of the filler. When the skeleton structure was stable, the filling action of the filler was more pronounced. The frost heaving of an MFH filling material is in fact a dynamic equilibrium process between the filling and lifting actions of the filler.
Abstract: To address the adverse effects of the frost heaving of subgrades in regions with seasonal frozen soil on the smoothness of high-speed railway tracks, the effects of several factors—including filler, water content and external loading—on a micro-frost-heaving (MFH) filling material were studied through laboratory experiments and theoretical analysis...
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An Improved Method for Earthquake Damage Prediction of Highway Subgrade and Pavement Based on Closeness Degree Method
Jia Lee,
Junqi Lin,
Jinlong Liu
Issue:
Volume 6, Issue 4, July 2018
Pages:
118-122
Received:
16 September 2018
Published:
18 September 2018
Abstract: In this article, based on the earthquake damage data of ‘5.12’ Wenchuan Earthquake and the improved method of earthquake damage prediction of highway subgrade and pavement which is obtained by using nonlinear regression method, a new method using closeness degree is given. This new method uses fuzzy recognition to determine the earthquake damage level of certain road section. In order to conduct fuzzy recognition, the membership function of the fuzzy set of the damage grade is also given, after conducting fuzzy recognition for membership function of earthquake damage using closeness degree method, the earthquake damage prediction results of corresponding road sections will be obtained. Finally, an example is given based on the data of earthquake damage in Wenchuan earthquake. The results of the example show that this new method of earthquake damage prediction using closeness degree indeed has higher accuracy, which proves it another effective and practical method for earthquake damage prediction of highway pavement and subgrade. This method also provides a reference for future research on related projects.
Abstract: In this article, based on the earthquake damage data of ‘5.12’ Wenchuan Earthquake and the improved method of earthquake damage prediction of highway subgrade and pavement which is obtained by using nonlinear regression method, a new method using closeness degree is given. This new method uses fuzzy recognition to determine the earthquake damage le...
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Research on Optimization of Public Service Facilities Land Efficiency in Changchun City Based on Compact City
Issue:
Volume 6, Issue 4, July 2018
Pages:
123-133
Received:
17 October 2018
Published:
18 October 2018
Abstract: With the continuous development of the social economy, the city has a chaotic image of unwarranted expansion, so the proposal of compact cities and stock planning has been very important. Land for public service facilities is a major component of urban functional land, so it can be used to reflect the compactness of urban land. Based on the background of compact city, this paper analyzed the service efficiency of public service facilities land in Changchun City, including land for educational and cultural facilities, sports facilities, medical and health facilities and social welfare facilities. Through GIS and other technical means to process the data, and comprehensive analysis of the number of facilities, spatial distribution and accessibility analysis, the results of spatial allocation were obtained. In order to consider the behavioral factors of human beings, these results were divided into suppliers, suppliers and demanders for comparative analysis, and the influencing factors and their interrelationships leading to these results were obtained. At the same time, this gave specific suggestions on regional control, spatial structure compactness and spatial element allocation from the macro, meso and micro levels. Furthermore, it will give the relevant planning department measures and recommendations about optimizing the space efficiency of land use for public service facilities.
Abstract: With the continuous development of the social economy, the city has a chaotic image of unwarranted expansion, so the proposal of compact cities and stock planning has been very important. Land for public service facilities is a major component of urban functional land, so it can be used to reflect the compactness of urban land. Based on the backgro...
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Experimental Study on Interfacial Shear Properties of Concrete Reinforced Stone Arch Bridges
Issue:
Volume 6, Issue 4, July 2018
Pages:
134-140
Received:
7 November 2018
Published:
8 November 2018
Abstract: To investigate the shear performance of the interface between concrete and stone, the interfacial shear test of concrete - stone carried out by using the Z-type and hoop-type specimens. The effects of different bonding methods, material strength and different forms of embedded steel bars on interfacial shear properties are considered.. The experimental results show that the bonding interface between concrete and stone is the weak point of the sample, and the damage occurs on the interface. The fracture pattern of Z-type specimen is vertical crack and diagonal crack near the interface. The crack forms of the hoop type specimens are the diagonal cracks distributed on the top of concrete, vertical and oblique cracks on the sides. Within a certain range, the strength g of the concrete will increase the shear strength of the interface and delay the cracking of the specimen. When the strength grades of concrete were C35, C40 and C45, the shear strength of the Z-type specimen increased by 14.7% and 10.8% respectively, and the shear strength of the hoop-type specimen increased by 15.2% and 11.1% respectively. Interfacial implantable steel bar can improve the shear resistance of interface significantly, and the greater the rate of steel bar, the greater the shear strength. When the planting rates were 0%, 0.196%, 0.392% and 0.785% respectively, the improvement rates of shear strength of Z-type specimens were 40.2%, 65.5% and 45.2% respectively, and the improvement rates of shear strength of hoop specimens were 64.1%, 54.5% and 60.5% respectively. The shear strength of the hoop type specimen is greater than that of the Z-type specimen, the non-planted bar specimen is increased by about 20%, and the planted steel bar specimen is increased by about 40% to 55%.
Abstract: To investigate the shear performance of the interface between concrete and stone, the interfacial shear test of concrete - stone carried out by using the Z-type and hoop-type specimens. The effects of different bonding methods, material strength and different forms of embedded steel bars on interfacial shear properties are considered.. The experime...
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