The hydraulic fracturing method is a common method to measure the ground stress. This article describes the principles of the hydraulic fracturing method, studies the distribution and the value of the ground stress in a tunnel area with the hydraulic fracturing method, and predicts rock burst by using the Russenes discriminance and the Turchaninov discriminance. The results show that the maximum horizontal stress is between 4.7MPa and 11.1MPa, and the minimum horizontal stress is between 4.0MPa and 8.0MPa. The maximum horizontal stress direction of the drilling is between N63 °W and N72 °W, and it is not conducive to the stability of the tunnel surrounding rocks because the large angle intersection of the tunnel axis direction and the maximum horizontal stress direction.
Healthy urban river ecosystem is the important symbol of the sustaining development of a city. This thesis discussed the issues of the ecosystem health situation of Panlong River, an urban river in Kunming city. This can provide the reference and scientific strategy for the government to renovate the urban river comprehensively. Using the comprehensive index evaluation method, we selected some indicators to characterize the main features and functions of urban river ecosystem to establish a comprehensive index system for evaluating urban river ecosystem health. These indicators included six aspects: water quality indicators, aquatic life indicators, hydrology indicators, river channel indicators, riparian zone indicators and social indicators. Total of them are 20 indicators. And the evaluation criteria was ascertained. Analytic hierarchy process (AHP) method was used to determine the weight of the indicators and the comprehensive assessment model was also built. Pilot study results indicate that the ecosystem of Panlong River in Kunming city is in the health status in 2011. The results showed that the comprehensive renovation of the Panlong River was very effective. Based on the ecosystem health assessment results of Panlong Rive and evaluation score of each indicator, we made certain the limiting factors that affect the urban river ecosystem health, which are vegetation of riparian zone, the water quality, aquatic habitat, the curve situation of the river channel, the form of bank protection, etc. And some suggestions were also provided for Panlong River ecological restoration.
Performance of the smoke exhaust system in two atria with nonuniform spaces will be analyzed by fire models in this paper. A two-layer zone model and a Computational Fluid Dynamics field model FDS developed by the Building and Fire Research Laboratory, National Institute of Standards and Technology, USA are used. Numerical results are compared with the experimental data by hot smoke test in these two atria. Both fire models can give good predictions and so are suitable for evaluating the performance of the smoke exhaust system.
The fire in high-rise buildings is perhaps more dangerous than those occur in normal buildings because of the strong stack effect and wind effect on the fire. The wind effects on the wind flame spread across the exterior wall of the high rise building are studied in this paper by the numerical methods. The results show that high wind speed will change the wind flame spread direction and make the room inclined above the fire room more danger, especially the room at the same floor adjacent to the fire room. Special passive fire protection measures should be taken under these kinds of conditions.
Vertical spread of opening spill plume from underground garage fire is studied by FDS. How can cornice barrier prevent the vertical spread of opening spill plume under the effect of the thermal buoyancy is analyzed. Optimal technical solutions and design parameters are proposed to improve the fire safety of underground building and adjacent buildings. This study can provide theoretical and technical reference for the underground building design.
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