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Guo H.,Southwest Jiaotong University | Yao L.,Southwest Jiaotong University | Yao L.,MOE Key Laboratory of High speed Railway Engineering | Yao L.,China Institute of Technology | Sun S.,Southwest Jiaotong University
Journal of Modern Transportation

In the feasibility stage of the transport route selection, large-scale geological investigations are advised before the route is determined. Therefore, rapid assessment of seismic landslide zones can be completed by the second development of the ArcGIS program. A large amount of geological information can be obtained by this method which is based on existing remote sensing image data. The integrated data can then be used to guide route location selection. This method assesses the angle between the main axis of the slope and the axis of the route and produces a zoning map that identifies slopes that threaten the route by combining with other characteristics including the climate in the study area, and the lithology and seismic structure of the near-field region. A hazard-zone map showing the degree of earthquake-induced landslide can be quickly generated by the comprehensive index method. The seismic landslide zone map was verified by comparison with the findings of a geological engineering survey conducted in the study area. © 2015, The Author(s). Source

Luo Y.,Southwest Jiaotong University | Yao L.-K.,Southwest Jiaotong University | Yao L.-K.,MOE Key Laboratory of High speed Railway Engineering | Yao L.-K.,China Institute of Technology
Chinese Journal of Engineering Design

The scheme evaluation of mountain railway location design has the characteristic that it has many qualitative indexes. The traditional evaluation methods have not fully taken the uncertainty characteristics of qualitative indexes into account, and it also lacks of appropriate evaluation methods when qualitative indicators and quantitative indicators cross with each other. Firstly, the advantages of the cloud model in describing uncertain information were used to improve the traditional AHP. Combined with deviation method, the subjective weight and objective weight of index were calculated respectively. Through a new weighted fusion mode, the combination weight was formed. Then, according to the principle of uncertain reasoning of cloud model, an effective quantification of qualitative indexes was achieved by using the cloud generator based on the evaluation about qualitative index made by experts using linguistic variables. Finally, the projection method was introduced to select the optimal scheme. Therefore, a new model of comprehensive scheme evaluation which contained both quantitative and qualitative indexes was proposed, and an example of local alignment scheme comparison was used to illustrate its feasibility and practicability. It provides a new idea and method for the scheme evaluation of railway location design in mountains. Source

Huang Y.,Southwest Jiaotong University | Yao L.,Southwest Jiaotong University | Yao L.,MOE Key Laboratory of High speed Railway Engineering | Yao L.,China Institute of Technology | And 2 more authors.
Yingyong Jichu yu Gongcheng Kexue Xuebao/Journal of Basic Science and Engineering

2Based on the detailed data of “4·20” Lushan Earthquake from VII to IX seismic intensity zone, the distribution law of landslides triggered by earthquakes in different seismic intensity zones was explored. The mechanism is interpreted from a physical point of view. The field data shows that there exists a power-law relationship between the area and frequency of landslides in IX, VIII, VII seismic intensity zones. Exponent b of the power-law in different zones is closed. But with the decline of the seismic intensity, the density of landslides decreases monotonically. The cellular automaton simulation reveals that the dynamical mechanism of sand-pile model is subject to the same power-law distribution, with 0. 5 decline ratio of disturbance intensity. The density of avalanche decreases linearly. Physics experiments with shaking table sandpile model also support above results. It is concluded that the power-law relationship between the scale and frequency is the basic regulation of landslides triggered by earthquakes from VII to IX seismic intensity zone. Different densities may serve as a major indicator of various intensities of damage. The research results may be used to provide scientific basis to sketch and assess the mountain disasters triggered by earthquake. ©, 2015, The Editorial Board of Journal of Basic Science and Engineering. All right reserved. Source

Zhu H.-W.,Southwest Jiaotong University | Yao L.-K.,Southwest Jiaotong University | Yao L.-K.,MOE Key Laboratory of High speed Railway Engineering | Jiang L.-W.,Southwest Jiaotong University | Qiu Y.-L.,Southwest Jiaotong University
Yantu Gongcheng Xuebao/Chinese Journal of Geotechnical Engineering

The deformation failure modes of gravity retaining walls under earthquakes are investigated by using the near-field data in Wenchuan Earthquake. It is found that the deformation failure modes of the retaining wall more closely relate with the foundation. The wall on the rock foundation mainly exhibits inclination deformation, while the wall on the soil foundation mainly shows slip deformation. Based on the Winkler foundation model, the soil mass is viewed as the combination of a set of springs and ideal rigid plasticity objects, and the relevant methods for the seismic earth pressure and the point of resultant force for gravity retaining wall under different displacement modes are proposed. The results show that the distribution of seismic earth pressure can be expressed differently under different deformation failure modes, except the slip deformation, and that the distribution of seismic active earth pressure against retaining wall is nonlinear under the rest of the deformation failure modes. The point of resultant force for the gravity retaining walls on the rock foundation is higher than that of the walls on the rock foundation. Large-scale shaking table tests for gravity retaining walls on rock foundation and soil foundation are conducted to test the proposed theory. It is indicated that the experimental results are in accordance with the theoretical ones. Source

Su Q.,MOE Key Laboratory of High speed Railway Engineering | Li X.,Southwest Jiaotong University | Bai H.,Southwest Jiaotong University
Applied Mechanics and Materials

A series of tests based on large scale model are designed to study dynamic response of pile-broad subgrade, aiming at structure's response towards different load frequency and structure's performance under long-term dynamic load. The test results indicate that dynamic stress of reinforcement and soil decrease slightly with load frequency, while accelerations trend to increase. Soil under loading plate has certain supporting effect because stress of reinforcement is smaller in test group with soil remains. Performance of pile-board subgrade under long-term dynamic load is steady and reliable since none of stress and displacement varies obviously when loading times increase to 10 6. Ultimate bearing capacity of pile-board subgrade is much bigger than actual demand, so the structural type of pile-broad plate remains to be optimized. © (2011) Trans Tech Publications, Switzerland. Source

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