Table of Contents
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Article
by Xin-Rong Wang
2020,
9(1);
doi: 10.18686/mt.v2i1.1356
106 Views,
0 PDF Downloads
During the construction and service of high-speed railway slab ballastless track, the structural material parameters may change, which is quite different from its engineering design values. At present, there is still a lack of in-depth research on the impact of this change on the damage of the interface between the track slab and the mortar layer. In this paper, the finite element model of CRTS II slab ballastless track is established. Cohesive force model is used to simulate the damage behavior of the interface. The influence of the elastic modulus of the track slab, the elastic modulus of the mortar layer and the interfacial bonding strength on the damage of the interface between the track slab and the mortar layer under the extreme temperature gradient load of 90 C/m is analyzed. The results show that the influence of elastic modulus of track slab and mortar layer on the interface damage is basically the same. High elastic modulus deteriorates the interface stress and will increase the interface damage degree and damage area. The interfacial bonding strength has a significant effect on the interfacial damage. When the bonding strength is less than its design value, the interfacial damage rapidly deteriorates with the decrease of the bonding strength.
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Article
by Junyi Han
2020,
9(1);
doi: 10.18686/mt.v5i1.1372
97 Views,
0 PDF Downloads
The definition of degree in complex network is extended based on the lane attributes (number, width and direction) of urban road network. The connection characteristics of intersections and road elements in urban road network under primitive and dual methods are studied respectively. Considering the cognitive characteristics of actual road network and residents’ travel, intersections are defined as nodes, based on named road method. With Stroke-like analysis, road elements are defined from the perspective of residents’ cognition, and the concept of primitive degree is improved by combining the number of motor lanes. Under the new definition of road network elements, the average nearest neighbor degree method based on improved measure is used to analyze the connection characteristics between intersections and roads, and considering the shortcomings of existing methods, the paper puts forward a new concept of primitive degree. The concept of connection coefficient is better defined, and the analysis method is validated by taking the main urban area of Xiamen as an example, and the characteristics of road network connection in the main urban area are analyzed. The results show that the urban intersection element network and road element network are scale-free networks with power exponents of 1.69 and 2.70, respectively. The connection of road network elements takes a critical node as a segment characteristic, and the value of the adjacent points of connection coefficient based on improvement degree is 3.40 and 8, respectively. From this point of view, the urban road network is not a simple homogeneous or heterogeneous network; the proposed method for analyzing the connectivity characteristics of road network elements is used to understand the topological characteristics of urban road network and the evolution model of road network. The construction is of great significance. |
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Article
by Ming-Liang Li
2020,
9(1);
doi: 10.18686/mt.v2i1.1358
92 Views,
0 PDF Downloads
This paper introduces the seismic response mechanism of subway stations and the different responses of semi-ground side platform stations under earthquake action, compares different seismic calculation methods, and combines the actual engineering to carry out the reaction displacement and response spectrum of a semi-ground subway station in the 8 degree earthquake-resistant area. Seismic analysis of the method is used to study the seismic response law of the semi-ground side platform subway station, in order to provide a basis for the seismic design of the semi-ground side platform station. |
