Full Issue
View or download the full issue |
Table of Contents
Article
by Guangxing Xu, Minming Yan, Zhaohong Li
2019,
8(1), 5-11;
doi: 10.18686/mt.v8i1.2004
158 Views,
0 PDF Downloads
In order to improve the seismic behavior of the existing rigid anti-slide piles, a new type of energy-consumption double-limb anti-slide pile was proposed. The new pile is composed of a main pile limb, an auxiliary pile limb and some energy-consumption connecting rods, which can significantly increase the energy dissipation of the slope and its supporting system during earthquake. Three numerical models of s lopes, which are non-supported slope, traditional rigid anti-slide pile supported slope and new energy-consumption double-limb anti-slide piles supported slope, were established respectively by Flac3D finite difference software. The deformation, shear strain increment, point safety factor and earth pressure behind piles of each slope model under earthquake were compared and analyzed. The results is how that the horizontal displacement of the slope supported by energy-consumption double-limb anti-slide piles is similar to that supported by rigid anti-slide piles with the same cross-section, but the horizontal displacement of the soil behind the piles is larger, which increases the dissipation of the seismic input energy. The vertical displacement of the slope supported by energy-consumption double-limb anti-slide piles is smaller than the slope supported by rigid anti-slide piles, which can effectively control the overtopping failure of the slope. The energy-consumption connecting rods yield continuously and plastic deformation occurs during earthquake, which dissipate a lot of energy. Meanwhile, the deformation of the main pile limb is reduced, and the overall safety of the anti-slide pile is guaranteed. The energy-consumption double-limb anti-slide piles can significantly reduce the shear strain and earth pressure behind piles, and improve the point safety factor of the slope supported by it, which have better seismic performance than the rigid anti-slide piles, and can significantly improve the seismic stability of the slope. |
Article
by Libo Cao, Leqi Zhang, Lingbo Yan, Zheng Chen, Guoliang Xiang
2019,
8(1), 12-16;
doi: 10.18686/mt.v8i1.2005
210 Views,
0 PDF Downloads
Obtaining the accurate position information of the vehicle is of great significance for the intelligent driving assistance system. Due to the relative positioning accuracy based on Global Positioning System is not high enough and the signal is unstable, and the positioning system based on wireless communication needs to lay a large number of roadside units, a relative positioning method based on vision and V2X is proposed. The error distribution of the positioning method is analyzed, and the positioning result is Kalman filtering. The results show that the relative positioning system can achieve positioning accuracy within 0.38m of the smooth straight road and 0.35m of the curved and large undulating road, and its positioning stability can be improved after Kalman filtering. |
Article
by Youyi Ge, Xing Zhao, Hao Lin, Jinghao Liu, Bailiang Zhou
2019,
8(1), 17-20;
doi: 10.18686/mt.v8i1.2006
175 Views,
0 PDF Downloads
Based on the theory of urban traffic network flow, this paper studies the influence of the setting of urban tidal lane on the traffic distribution in the regional road network. According to the influence mechanism of tidal lane's setting on road network facilities, the sensitivity of road network traffic flow after tidal lane's setting to free travel time, road section capacity and OD travel demand is studied and analyzed, and the sensitivity equation of tidal lane's input variables in the equilibrium network to road section traffic flow is established, thus analyzing the influence of tidal lane's setting on road network traffic flow. By analyzing the changes of road flow on the road network before and after the setting up of tidal lane, an effective analytical method is provided for analyzing the impact of the setting up of tidal lane on the road network. |
Article
by Bo Wang, Yong Yu
2019,
8(1), 21-26;
doi: 10.18686/mt.v8i1.2008
177 Views,
0 PDF Downloads
Stress and deformation of surrounding rock are basic issues in tunnel engineering, directly affecting the safety evaluation and the support or lining measures to a tunnel. Kastner formulae proposed in 1950s describe the plastic zone range of a circular tunnel and the stress distribution in plastic zone, and have served as the theoretical basis of tunnel analysis in past decades. Supposing the surrounding rock is ideal elastic-plastic material with Mohr-Coulomb or Mises criterion, we proved that the support process to a circular tunnel is an unloading process in terms of plastic mechanics. The conclusion was verified by FLAC calculation. Both the stress increment and the displacement increment of surrounding rock in support stage are consistent with the elasticity theory. Therefore, Kastner formulae are only applicable to the excavation stage of tunnel, not to the support stage. |