Papers by Keyword: Stability Analysis

Abstract: Seepage damage has been one of the most important factors that affect the safe operation of embankment dams, So more consideration is taken into the saturated soil more than non-saturated soil. In this paper, we carry on the experiment by using SEEP/W software to take the flow field analysis of unsaturated soil of the core embankment dam. Based on the experiment, we analyzed the normal water level of dam seepage line, checked the flood level lower position, the pressure and the flow hydrodynamic calculations of the dam such as hydraulic slope, analyzed different water seepage under the dam changes, as well as the reason of the causing damage to the dam and the effect on the heart wall seepage is also analyzed. We found that the reason of dam destroyed is due to the hydraulic slope caused by excessive exports, we propose the corresponding seepage control measures. To solve this problem, we conducted the filtration for the seepage export processing.

Abstract: In emergency, the crowd evacuation from public buildings is the most important issue to save human lives. Panic generation and spread normally can lead to the unstable state -stampede during the crowd motion. The stability of crowd evacuation is a complex problem being researched for decades. This paper introduces self-organized criticality(SOC) theory to build the mapping model from a collective crowd into a sand pile with SOC. Therefore, the complex problem of stability analysis for crowd evacuation is converted into sandpiper stability analysis in a relatively simpler way.

Abstract: Stability analysis of steep rock bedding slope with weak structure planes using strength reduction method was simulated in this paper. The post processing function can display the development condition of the plastic zone, which is the criterion for instability of the slope. Analysis with working conditions of natural circumstance, after excavation, and the slope reinforced by anchor shank after excavation were put forward. Failure modes and safety coefficients of the slope proved that weak plane is the main factor controlling slope failure. Simulation results shown that strength reduction method is appropriate in predict the shape and position of the potential failure surface of steep rock bedding slope.

Abstract: Taking Liang Zhuang phyllite tunnel as the research object, the paper tries to analyze the variation rules of formation stress and initial support stress in the construction process based on numerical simulation of surrounding rocks grade III, IV and V, and also by using the measured data to have a better analysis of the stress state of surrounding rocks and support in the construction process, thus to grasp the rules for better construction. The result shows that the maximum compressive stress of initial support increases in the process of excavation, while the maximum formation stress is relatively stable in the process of excavation, with a slightly down trend, and whether there is a rock bolt or not, it doesnt have an obvious effect on the distribution and size of initial support stress.

Abstract: To study the mechanical performance and stability of tied-arch bridge under structural defects and damages, limited element modal of Panzhihua Luoguo Jinshajiang Bridge was established and analyzed. Firstly, some typical damage models and their influence factors were presented. Then, based on the model established, change of suspender force caused by arch rib lineation defect, hanger lineation defect and boom failure was calculated respectively. The stability safety factor under the load group composed of dead load, live load and wind was calculated as well as the second-class nonlinear stability safety factor under structural initial defect. Calculation results shows that, suspender forces were more sensitive to archs vertical defect than to transverse defect. While, short hangers were more sensitive to lineation defect than long ones, and secondary inner force in short booms were bigger than in long ones. The result also tells that lateral wind is bad to lateral stability. Lift wind, somehow, makes positive contribution to structures in-plane stability. Structural initial defect can draw down the second-class stability safety factor under geometric nonlinear condition.

Abstract: According to the actual progress of a certain Surface Mine and based on strength reduction method, the deformation and fracture processes of the high dip bedded soft rock slope was simulated with RFPA-SRM, the stability of the slope was calculated. By analyzing the numerical simulation results, the characters of the deformation of high dip bedded soft rock slope and the landslide mode were demonstrated, which could provide a scientific basis for reasonable landslide control measures.

Abstract: In this paper, taking a subway station as the design background, combining with the design conditions and the surrounding rock stability, hydrogeology conditions, and using numerical simulation and engineering analogy method, the main structure of the station excavation section is excavated and the tunneling segment supports is designed. Using FLAC3D software to build a subway station tunneling segment model, with reference to the analog out of the design parameters and excavation program, strictly in accordance with the small block and step into the ring principle, the excavation and support are simulated, and the numerical calculation is performed, then from the stress, displacement, plastic zone and other aspects, the station shallow section stability of the support is analyzed, the effect of excavation station bringing to the surrounding soil stability is calculated.

Abstract: With the rapid development of the economic construction in loess region, a large number of cutting slope excavation engineering were done in order to pioneer more construction space. The safety of this kind of project is worrisome because the scale of excavation is increasing and the cutting height of slope is rising. A high slope in Yan’an is selected for typical case and the stability of the slope is calculated by GTS software. The process of the deformation and destruction are analyzed and predicted from the relationship between the stress and the strength of the most dangerous slip surface. The research results can not only services in the engineering construction directly, but also play a guiding role to engineering construction in the loess region in China.

Abstract: Basket handle arch bridge with reinforced concrete shortens the distance between the arch rib compared with parallel arch rib bridge, improves the lateral stability, predecessors have done a lot of research on basket handle narrow arch bridge, but the study of wide span arch bridge is insufficient, conduct load test on a wide basket handle arch bridge which 33m wide and mainspan is 90m, the test results show that the large width-span ratio arch bridge has higher bearing capacity, but vertical bearing capacity is not improved, the dynamic coefficient increases when the speed is higher than 30km/h, the measured dynamic coefficient at jumpy driving is relatively large, the dynamic coefficient is significant when jumpy driving speed is 10~15km/h.

Abstract: To enhance the carrying capacity of the crane variable cross-section telescopic boom, the usual practice is using the cable at its top end, it makes the out-of-the-lifting plane stability problem of crane telescopic boom become solving the Euler critical force with follower force. This paper established the deflection differential equations of crane telescopic boom model which under actions of cable, with proper boundary conditions, the recurrence formula of buckling characteristic equations were presented, and some practical applications were given. The influence on buckling critical force of crane boom due to the ratio of the length of cable and crane boom was discussed. Took certain four-sectioned telescopic boom as example, the destabilizing critical force was calculated, the result showed that in comparison with the ANSYS method, the buckling characteristic equations in this paper is completely correct.