Numerical Simulation of Flash Floods Routing Based on Improved Leap-Frog Method

2013 ◽  
Vol 347-350 ◽  
pp. 2173-2177
Author(s):  
Jia Hua Zhang ◽  
Chi Zhang

in the 2-d numerical simulation of flash flood disaster, due to flood often occurred in the steep terrain and water flow rapidly changed, lead to that the calculated value is unstable and even the calculation diverge in the simulation. This paper presents a grid outflow correction method, which is based on the leap-frog finite difference format, through modifying the outflow rate of the grid circularly, to ensure the mass conservation in the whole process of computing. In the local dam bursting model, the simulated result comparison of the grid outflow correction method and the algorithm of implicit alternating direction on the mass conservation shows that, the new method can ensure the simulation accuracy and the numerical stability under the condition of steep terrain and moving boundary. According to the proposed method, the simulation analysis in the process of extreme flash flood disasters which happened in 2010 Zhouqu county in Gansu province was carried out. The comparison of simulation results and remote sensing estimation results shows that the deviation of the flood evolution time, speed and impact height are within 5%, and the consistency of evolution path is good, which verifies the validity of the algorithm.

2013 ◽  
Vol 387 ◽  
pp. 180-184
Author(s):  
Ya Dong Li ◽  
Hai Hong Mo ◽  
Jun Shen Chen

The numerical simulation analysis on the whole process of the tube immersing is researched, which use computational fluid dynamics method, is based on RNG k~ε turbulence model. The analysis shows that: additional pressure of tube lateral wall depends on the changed flow field cause by tube immersing; through the analysis, it have explored the special position of additional pressure changes in the process of immersing; it also shows some problems should be paid attention, through analysis the stress of special position.


2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Kai Zhang ◽  
Xiaojie Yang ◽  
Xuebin Cui ◽  
Yong Wang ◽  
Zhigang Tao

Nanfen open-pit iron mine is the largest single open-pit mine in Asia. Because of the lag of the extension project, the section has slowly spread in the shape of “V,” and disasters such as landslides occur frequently. In this study, first, the NPR anchor cable monitoring, which shows supernormal mechanical characteristics and can realize the monitoring and early warning target for the whole landslide process and early warning curve of bedding rock “2016-1101 landslide” in the lower wall of Nanfen open-pit mine, was analyzed, revealing the failure process of the bedding rock landslide and the force evolution characteristics of the NPR anchor cable. Then, based on the Fish language in FLAC3D and 3DEC software, the mechanical model of the NPR anchor cable was constructed, and numerical simulation was performed on the whole process of “16-1101 landslide” induced by accumulation of old landslide body. The results of this study indicate that the stress monitoring curves and failure characteristics of the NPR anchor cables in the whole process of landslide by the two numerical simulation methods are basically consistent with the field measurement results, providing a theoretical and practical basis for the mechanistic analysis and numerical simulation of other similar slopes.


2013 ◽  
Vol 361-363 ◽  
pp. 1150-1154
Author(s):  
Liang Yan Mao ◽  
Chang Qing Wang ◽  
Li Yong Zhang

6m arch board used as test object, this paper introduces the arch in different level of load board cracks, development and production of plastic hinge until the whole process for all the damage simulation numerical simulation analysis then compared with experimental results and analysis of increased with load crack distribution, which can be used to understand the similar in service work condition of the stone bridge.


2011 ◽  
Vol 90-93 ◽  
pp. 1812-1818
Author(s):  
Hong Ye Chen ◽  
Jing Fei Zhang ◽  
Hui Zhong Ma ◽  
Jin Ying Ma

In order to study and demonstrate the safety condition of urban track transportation system in mechanics area, and to determine the key points and difficulties of this system, it uses FLAC3D numerical simulation software, combines the applied examples of engineering projects, carries on simulation analysis on aspects of surrounding soil’s deformation rule during construction stages, the mechanics analysis during main structure’s construction, and the system surrounding soil’s stress-strain rules during operation stages, etc.. Feasible safety measures and suggestions were proposed accordingly. The applied research indicates that the numerical simulation analysis can express the risk characteristics and rules well during engineering construction and after construction, and further avoid potential hazards or accidents’ occurrence, which has important meanings for ensuring the safety of engineering projects during the whole process.


Author(s):  
Luan Labigalini ◽  
Ricardo Salvo ◽  
Rafael Sene de Lima ◽  
Ismael Marchi Neto ◽  
Rodrigo Corrêa da Silva

Author(s):  
Yu NISHIO ◽  
Makoto YAMAUCHI ◽  
Seiichiro IZAWA ◽  
Yu FUKUNISHI

2021 ◽  
Vol 11 (11) ◽  
pp. 5283
Author(s):  
Jui-Ching Chou ◽  
Hsueh-Tusng Yang ◽  
Der-Guey Lin

Soil-liquefaction-related hazards can damage structures or lead to an extensive loss of life and property. Therefore, the stability and safety of structures against soil liquefaction are essential for evaluation in earthquake design. In practice, the simplified liquefaction analysis procedure associated with numerical simulation analysis is the most used approach for evaluating the behavior of structures or the effectiveness of mitigation plans. First, the occurrence of soil liquefaction is evaluated using the simplified procedure. If soil liquefaction occurs, the resulting structural damage or the following mitigation plan is evaluated using the numerical simulation analysis. Rational and comparable evaluation results between the simplified liquefaction analysis procedure and the numerical simulation analysis are achieved by ensuring that the liquefaction constitutive model used in the numerical simulation has a consistent liquefaction resistance with the simplified liquefaction analysis procedure. In this study, two frequently used liquefaction constitutive models (Finn model and UBCSAND model) were calibrated by fitting the liquefaction triggering curves of most used simplified liquefaction analysis procedures (NCEER, HBF, JRA96, and T-Y procedures) in Taiwan via FLAC program. In addition, the responses of two calibrated models were compared and discussed to provide guidelines for selecting an appropriate liquefaction constitutive model in future projects.


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