Research on Back Analysis of Parameters for Excavation of the Underground Cavern Group of a Large-Scale Hydro-Power Station by Using Orthogonal Optimization

2012 ◽  
Vol 170-173 ◽  
pp. 3356-3360
Author(s):  
Wen Dong Yang ◽  
Xi Chao Gao ◽  
Yan Mei Zhang ◽  
Jia Yang ◽  
Gang Wang ◽  
...  

Engineering rock mass is a highly complex grey system, it is impossible to get all the parameters of rock mass by theoretical methods or field measurement approach. Underground engineering feedback analysis method is a reliable way to improve the design, optimization and construction. Based on the field data of underground cavern of a large-scale hydro-power station, the three-dimensional finite element model is established, and orthogonal experimental design and multi-objective optimization method are used for the rapid back analysis. This method could be used for obtaining the rock parameters by inversion calculating in the underground cavern construction of a large-scale hydro-power station. Meanwhile, the inversion parameters could also be applied in the excavation simulation for the next phase and the rock deformation and stability is predicted afterwards. The design and construction sectors are supposed to get its feedback in time, which effectively guarantees the stability of the surrounding rocks.

2013 ◽  
Vol 838-841 ◽  
pp. 705-709
Author(s):  
Yun Hao Yang ◽  
Ren Kun Wang

Large scale underground caverns are under construction in high in-situ stress field at Houziyan hydropower station. To investigate deformation and damage of surrounding rock mass, a elastoplastic orthotropic damage model capable of describing induced orthotropic damage and post-peak behavior of hard rock is used, together with a effective approach accounting for the presence of weak planes. Then a displacement based back analysis was conducted by using the measured deformation data from extensometers. The computed displacements are in good agreement with the measured ones at most of measurement points, which confirm the validities of constitutive model and numerical simulation model. The result of simulation shows that damage of surrounding rock mass is mainly dominated by the high in-situ stress rather than the weak planes and heavy damage occur at the cavern shoulders and side walls.


2021 ◽  
Author(s):  
Yang An ◽  
E-chuan Yan ◽  
Xing-ming Li ◽  
Shao-ping Huang

Abstract As a main method of petroleum strategic reserve in China, underground water-sealed storage cavern owns lots of outstanding advantages, such as low operating costs, high safety, and land resource conservation. Main caverns are important structure in underground project and the layout parameters and excavation scheme will have significant impact on overall project quality. The optimization method of main cavern layout and excavation scheme was put forward by a proposed large-scale underground water-sealed cavern project in China. First, based on field survey results, the Hoek-Brown strength criterion combined with rock mass quality Q classification system was used to estimate the equivalent mechanical parameters of rock mass. Second, the numerical experiments were carried out by relying on 3 Dimensions Distinct Element Code (3DEC). The discontinuous medium model was adopted, and displacements of key points, maximum displacement values and volume of the plastic zone were used as evaluation indicators. Axial direction, buried depth, spacing and excavation scheme of main caverns have been optimized. Results showed that axial direction should adopt NW325°, buried depth of cavern roof should locate at -100m, and distance between adjacent main caverns should be 1.5 times the span (36m). The “jump excavation” mode was recommended in construction. That is, the caverns on both sides should be excavated first, and the middle cavern should be excavated later. This mode could effectively reduce the interaction effect between caverns. This method has the characteristics of easy data acquisition and strong operability. It could be used to guide design and construction of similar projects . As a main method of petroleum strategic reserve in China, underground water-sealed storage cavern owns lots of outstanding advantages, such as low operating costs, high safety, and land resource conservation. Main caverns are important structure in underground project and the layout parameters and excavation scheme will have significant impact on overall project quality. The optimization method of main cavern layout and excavation scheme was put forward by a proposed large-scale underground water-sealed cavern project in China. First, based on field survey results, the Hoek-Brown strength criterion combined with rock mass quality Q classification system was used to estimate the equivalent mechanical parameters of rock mass. Second, the numerical experiments were carried out by relying on 3 Dimensions Distinct Element Code (3DEC). The discontinuous medium model was adopted, and displacements of key points, maximum displacement values and volume of the plastic zone were used as evaluation indicators. Axial direction, buried depth, spacing and excavation scheme of main caverns have been optimized. Results showed that axial direction should adopt NW325°, buried depth of cavern roof should locate at -100m, and distance between adjacent main caverns should be 1.5 times the span (36m). The “jump excavation” mode was recommended in construction. That is, the caverns on both sides should be excavated first, and the middle cavern should be excavated later. This mode could effectively reduce the interaction effect between caverns. This method has the characteristics of easy data acquisition and strong operability. It could be used to guide design and construction of similar projects .


2013 ◽  
Vol 706-708 ◽  
pp. 560-564
Author(s):  
Yi Huan Zhu ◽  
Guo Jian Shao ◽  
Zhi Gao Dong

Soft rock is frequently encountered in underground excavation process. It is difficult to excavate and support in soft rock mass which has low strength, large deformation and needs much time to be out of shape but little time to be self-stabilized. Based on a large underground power station, finite element model analysis was carried out to simulate the excavation process and the results of displacement, stress and plasticity area were compared between supported and unsupported conditions to evaluate the stability of the rock mass.


2013 ◽  
Vol 367 ◽  
pp. 145-150
Author(s):  
Jia Lian Cao ◽  
Jun Yong Li ◽  
Chao Yan Wan

To complete the optimization of large-scale structure such as vehicle body efficiently, a new topology optimization method which combines with sub-structural analysis technology is proposed. With HyperWorks/Optistruct for a platform: first, the finite element model of the light rail vehicle body including sub-structure and non sub-structure is created; second, analyze the most dangerous condition using static reduction method which based on sub-structure technology, output the reduction matrix, generate the sub-structure; and then optimization model is defined including that design variables is the element density, objective function is the minimum volume fraction and constraint is the definition of stress, then enter the reduction matrix, and choose the non sub-structure area for topology optimization; Finally, based on the results, redesign the structure and get the improved one according to the technical requirements and practical experience.


2011 ◽  
Vol 55-57 ◽  
pp. 1947-1950
Author(s):  
Sheng Jie Di ◽  
Wen Tang Zheng ◽  
Jing Kui Zhang

The rock mass with polycrystalline aggregates is common geomaterial in civil and architectural engineering as well as hydraulic and hydro-power engineering. For this kind of geometerials, the study on the joint deformation parameters Kn and Ks and the calculation method are not enough so far. Focusing on the rock mechanics and engineering problems of columnar jointed rock mass related to Baihetan hydropower project, analytical models and numerical method based on 3DEC are employed to study the mechanical parameters. The joint deformation parameters Kn and Ks are back analysis using GRNN and the field data of load-bearing plate tests. The application shows that the calculation results are in good accordance with in-situ test results.


2011 ◽  
Vol 90-93 ◽  
pp. 760-763
Author(s):  
Yin Ping Qi ◽  
Lv Xiang ◽  
Wei Shen Zhu

A great number of large-scale hydropower stations are to be constructed in southwest China. Many of them feature great depth or high in situ stresses. In this paper, a coupled damage and rheology method is adopted for stability analysis of an underground cavern group with time effect to consider the rock deformation. Meanwhile, a new method considering the crackopening displacement is used for back analysis. The stability of the surrounding rock masses is then evaluated.


The augmented demand for the power across the globe has resulted in the growth of non-conventional sources of energy as an appendage to the conventional sources. The large scale grid connected wind power systems have become one of the better alternatives among renewable energy based power generation methods. However the intermittency of wind power is one of the major limitations in the effective harvesting of energy leading to its reduced worth. Several methods are proposed and implemented to overcome the issue of wind power intermittency. In this paper a coordinated approach between wind and dispatchable and geographically proximal hydro power station is proposed to enhance the value of wind power. A MATLAB SIMULINK model of a wind power station is developed. Three potential sites with the conducive operating conditions for the implementation of the proposed scheme have been considered for the analysis. The results obtained are correlated to the enhanced worth of wind power.


2011 ◽  
Vol 18 (2) ◽  
pp. 511-520 ◽  
Author(s):  
Wei-ya Xu ◽  
Wei-ping Nie ◽  
Xian-qi Zhou ◽  
Chong Shi ◽  
Wei Wang ◽  
...  

2012 ◽  
Vol 455-456 ◽  
pp. 1538-1544 ◽  
Author(s):  
Quan Sheng Liu ◽  
Jin Lan Li

The FEM positive analysis is made using H-K non-stationary creep constitutive model in this paper, the finite element program for non-stationary viscoelastic-plastic displacement back analysis is compiled combining the non-stationary viscoelastic-plastic program with the complex shape optimization method, and the displacement back analysis of soft tunnel engineering is conducted. The result indicates that the viscous aging characteristics of rock mass can be reflected objectively if rock mass is regarded as non-stationary viscoelastic-plastic model, and the plastic zone development of surrounding rock can be predicted considering the plastic flow of rock mass and regarding the back analysis results as the calculation parameters.


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