scholarly journals Research on the Inversion Method and Application of Random Mechanical Parameters for Arch Dam and Its Nearby Mountain Structure

2021 ◽  
Author(s):  
Xin Cao ◽  
Chao Jiang ◽  
Tianhua Li

First, prior distribution of the mechanical parameters of arch dam body and its nearby mountain rock mass was determined according to the meso-modelling of dam concrete and test data of its nearby mountain rock mass, and a finite element model of the arch dam and its nearby mountain was established. Based on Bayesian theory, random inversion objective function was established. Afterwards, inversion analysis of mechanical parameters was conducted with Differential Evolution Adaptive Metropolis (DREAM(SZ)) on the basis of Markov chain random theory, for the inversion of random distribution parameters of the elasticity modulus of dam concrete and overall deformation modulus. This method was applied to some high-arch dam project, and it was verified to be effective by the results.

2012 ◽  
Vol 204-208 ◽  
pp. 727-731
Author(s):  
Yuan Zhao ◽  
Liang Qing Wang ◽  
Ye Liang

Deformation modulus plays an important role in evaluating slope stability of rock mass and conducting the geotechnical engineering design. Based on the research of geological properties, physical and mechanical parameters of predominant rock mass types for different formations from Zhongxian to Wuhan, China, deformation modulus values of gas pipeline area were estimated by using rock mass classification method in this paper. Comparisons were made amongst different formulas based on GSI, RMR and Q methods to suggest range values of deformation modulus for predominant rock mass types of different formations which gives instructions to estimate strength parameters of rock masses for similar projects.


2013 ◽  
Vol 368-370 ◽  
pp. 1551-1555
Author(s):  
Si Yu Wu ◽  
Bo Huang ◽  
Rui Jun Liu

Firstly, the stability of the slope need to determine mechanical parameters of slope rock mass such as deformation modulus, Poissons ratio, cohesion and internal friction angle, etc. For intact rocks, the mechanical parameters mentioned before are easy to determined. While the stability of slope rock mass is controlled by the deformation and intensity. Therefore, how to determine the mechanical parameters of the structure is the key to analyze the stability of slope rock mass. This paper intends to set the slope rock mass below some extra-large bridge as the research object and use numerical calculation to determine the mechanics parameters of rock mass structure plane on the basis of rock sample mechanics test results.


2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Hao Gu ◽  
Zhongru Wu ◽  
Xiaofei Huang ◽  
Jintao Song

For dams and rock foundations of ages, the actual mechanical parameters sometimes differed from the design and the experimental values. Therefore, it is necessary to carry out the inversion analysis on main physical and mechanical parameters of dams and rock foundations. However, only the integrated deformation modulus can be inversed by utilizing the conventional inversion method, and it does not meet the actual situation. Therefore, a new method is developed in this paper to inverse the actual initial zoning deformation modulus and to determine the inversion objective function for the actual zoning deformation modulus, based on the dam displacement measured data and finite element calculation results. Furthermore, based on the chaos genetic optimization algorithm, the inversion method for zoning deformation modulus of dam, dam foundation and, reservoir basin is proposed. Combined with the project case, the feasibility and validity of the proposed method are verified.


Author(s):  
Anh Kiet Bui ◽  
◽  
Pakawat Sancharoen ◽  
Somnuk Tangtermsirikul ◽  
Ganchai Tanapornraweekit ◽  
...  

Safety evaluation is an important task to verify performance of a dam during its service. For an old dam, the material properties vary from the designed value significantly affecting structural performance. This study investigates the effects of material properties of dam concrete and foundation rock on the structural behaviour of an old concrete arch dam during operation. The dam safety is evaluated by using a three-dimensional finite element model (FEM). All main loads, such as water pressure, dam self-weight, and thermal load, are considered in the analysis. An existing 54-year-old concrete arch dam, located in a tropical climate region in Thailand, is employed as a case study. The analysis results show that deformation modulus of the foundation, modulus elasticity of concrete, and the variation of reservoir water level during operation are key factors affecting the dam response. With a deformability modulus of foundation and elasticity modulus of dam concrete, which are about 20 GPa and 44.2 GPa, respectively, a good agreement in dam deflections between the analysis and the current monitored data from plumb line equipment can be obtained. It should be noted that the material properties are different from designed value significantly. Finally, safety evaluation can be properly conducted based on current material properties.


2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Yijun Chen ◽  
Chongshi Gu ◽  
Bangbin Wu ◽  
Chenfei Shao ◽  
Zhongru Wu ◽  
...  

A new approach was developed for the inversion modeling of dam-zoning elasticity modulus for heightened concrete dam, with old and new concrete zones. The proposed inversion modeling procedure takes advantage of the improved cuckoo search (ICS) algorithm and improved particle swarm optimization (IPSO) algorithm to adjust the mechanical parameters, which are used as input. An objective function is constructed based on the horizontal displacement increment by using the finite element method (FEM) and statistical analysis of the prototype monitoring data. One ideal arch dam model and one actual heightened concrete dam were taken as examples. The proposed method was used to implement the optimal selection of the dam-zoning elasticity modulus. The inversion analysis results indicate that the mechanical parameters identification method for heightened concrete gravity dams proposed in this article is accurate and has a fast convergence rate. Consequently, it can be applied as a reliable model to identify the dam-zoning elasticity modulus in practical engineering applications.


2012 ◽  
Vol 524-527 ◽  
pp. 310-316 ◽  
Author(s):  
Pei Feng Sun ◽  
Tian Hong Yang ◽  
Qing Lei Yu ◽  
Wei Shen

With ShapeMetriX3D rock non-contact measuring technology, structural planes’ distribution of MiaoGou iron mine slope is got. Then, the Mont-Carlo method is used to create equivalent fracture network, with that scale effects and anisotropic properties of rock mass are studied by RFPA2D, considering different scales and directions in statistical window. The results show that both deformation modulus and the strength of the rock mass’s REV are 2.5 m. Furthermore, the strength ratio of filler to rock (K) and the strength of the rock mass fit the logarithmic relationship in rough, while the elastic modulus ratio of filler to rock (M) and the strength of the rock mass fit the linear relationship in rough. The strength of no joints rock mass is much stronger than three times of the strength of jointed rock mass, but the rock mass elastic modulus of no joints is less than 1.6 times of the elastic modulus of jointed rock mass. The research results are directive and have reference value for the study of anisotropy mechanical parameters of rock mass engineering.


2010 ◽  
Vol 33 (2) ◽  
pp. 153-158
Author(s):  
Mohamed Hassan Aboud ◽  
Mohamed Ahmad Osman

2021 ◽  
Vol 11 (2) ◽  
pp. 764
Author(s):  
Ivica Pavičić ◽  
Ivo Galić ◽  
Mišo Kucelj ◽  
Ivan Dragičević

The successful exploration of dimension stone mainly depends on the quality, size, and shape of extractable blocks of dimension stone. The investigated area is in the Pelješac Peninsula (Croatia), in the External Dinarides orogeny, built from thick carbonate succession, characterized by relatively small deposits of high-quality dimension stone. These conditions demand challenging geological investigations in the “pre-quarry” phase to find optimal quarry location. The size and shape of dimension stone blocks are mainly controlled by fracture pattern systems. In the rugged, covered terrains, it is very hard to obtain a satisfactory amount of fracture data from the surface, so it is necessary to collect them from the underground. Borehole camera technology can visualize the inner part of the rock mass and measure the fracture characteristics. The main conclusions are as follows: (1) the digital borehole camera technology provides a quick, effective, and low-cost geological survey of fractured rock mass; (2) statistical fracture distribution parameters, P10, fracture spacing, Volumetric Joint Count (Jv) based on borehole wall survey can reflect the integrity of rock mass, providing a solid decision-making base for further investment plans and dimension stone excavation method.


2013 ◽  
Vol 671-674 ◽  
pp. 1012-1015
Author(s):  
Zhao Ning Zhang ◽  
Ke Xing Li

Due to the environment, climate, loads and other factors, the pre-stress applied to the beam is not a constant. It is important for engineers to track the state of the pre-stress in order to ensure security of the bridge in service. To solve the problem mentioned above, the paper puts forward a new way to analyze the effective pre-stress using the displacement inversion method based on the inversion theory according to the measured vertical deflection of the bridge in service at different time. The method is a feasible way to predict the effective pre-stress of the bridge in service. Lastly, taking the pre-stressed concrete continuous rigid frame bridge for example, the effective pre-stress is analyzed by establishing the finite element model.


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