Shear Properties and Strength of Weak Intercalated Layers in Dam Foundation of Datengxia Power Station

2015 ◽  
Vol 723 ◽  
pp. 322-325
Author(s):  
Chun Tan ◽  
Zhi Fa Ma ◽  
Zhong Fu Liu ◽  
Dong He Ma ◽  
Yan Ping Li ◽  
...  
Keyword(s):  
Shear Strength ◽  
Mineralogical Composition ◽  
Gravity Dam ◽  
Stress And Strain ◽  
Dam Foundation ◽  
Composition And Structure ◽  
Shear Stress And Strain ◽  
Weak Intercalated Layer ◽  
Dam Stability ◽  
Main Factor

For gravity dam with weak intercalated layer in foundation,the shear strength of the weak intercalated layers is the main factor in the control of the dam stability. It is the key point of geological and experimental work to ensure the shear strength to satisfy safety and economy of dam. The material composition,mineralogical composition and structure,genetic type and characteristics of shear stress and strain of weak intercalated layer in dam foundation of Datengxiapower station are analyzed,the valuation rule of the shear strength of weak intercalated layer with plasticfailure mode is discussed,and finally the recommended geological value of shear strength of weak intercalated layer in this project is proposed.

Study on Gravity Dam Foundation Stability Combining with Dam Foundation Deformation Behavior

2011 ◽  
Vol 250-253 ◽  
pp. 2965-2969
Author(s):  
Xian Jun Wang
Keyword(s):  
Stability Analysis ◽  
Deformation Behavior ◽  
Selection Method ◽  
Gravity Dam ◽  
Node Selection ◽  
Dam Foundation ◽  
Foundation Deformation ◽  
Dam Stability ◽  
Foundation Failure ◽  
Key Nodes

Gravity dam foundation failure progress is always associated with its deformation development. So dam foundation deformation should be paid more attention in gravity dam stability analysis. Key node plays an important role in analyzing the dam foundation deformation development. But how to select key node is worth researching. A gravity dam foundation stability is studied by the development of plastic zone and key nodes’ displacements in dam foundation. The problem of key node selection is researched and a key node selection method is brought up also in this paper.

scholarly journals Protein-polyelectrolyte complexes. Part 3. Complexes bovine serum albumin with sulfonate-containing aromatic poly- and copolyamides

2019 ◽  
Vol 58 (4) ◽  
pp. 66-71
Author(s):  
Natalia N. Smirnova ◽  
◽  
Kirill V. Smirnov ◽  
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Bovine Serum ◽  
Aromatic Polyamide ◽  
Density Maximum ◽  
Degree Of Ionization ◽  
Polyelectrolyte Complexes ◽  
Composition And Structure ◽  
Carboxylic Groups ◽  
Main Factor

The interaction of bovine serum albumin in aqueous solution with sulfonate-containing poly- and copolyamides were studied. It was shown that, as a result of macromolecular reactions protein-polyelectrolyte complexes forms, stabilized mainly by electrostatic forces. To characterize the protein-polyelectrolyte complexes composition the r parameter used, which is defines as the ratio of mass concentration of polyelectrolyte and protein. It was shown that the main factor determining the composition and structure of forming protein-polyelectrolyte complexes is the degree of ionization of functional groups, interacting in the polyelectrolyte reaction that is determined by the nature of those groups and the pH of the solution. The presen ce of sulfonate and carboxylic groups in the copolyamide composition gives an extra opportunity to regulate the protein-polyelectrolyte interactions. Using spectrophotometry were established that, in the studied system when the aromatic polyamide and bovine serum albumin are mixed at optimal pH conditions (рН < 4.9), complexes are formed, the composition of which corresponds to the value of r ~ 0.15 g/g. The degree of conversation in protein-polyelectrolyte reactions is close to 0.8. The size of the formed particles was about 2.2 μm. In the case of aromatic copolyamides that contain both sulfonate and carboxylic groups, an increase in concentration of carboxylic groups to 42 mol. % leads to a shift of the optical density maximum on the curve of turbidimetric titration in to the higher r values (~ 0.18 g/g) at pH = 3.5, when the carboxylic groups are non-ionized. The size of the formed complex particles was about ~ 150.0 nm, the fraction of micron-sized particles is about 5%. The degree of released protein is based on the conditions under which reaction take place and varies from 93 to 99%. The result obtained during this work can serve as a base for the effective methods of isolation and purifying of the target proteins development.

FAILURE PATTERNS OF SHEAR KEYS AND SEISMIC RESISTANCE OF A GRAVITY DAM WITH LONGITUDINAL JOINTS

2014 ◽  
Vol 08 (01) ◽  
pp. 1450004 ◽  
Author(s):  
LIAOJUN ZHANG ◽  
HANYUN ZHANG ◽  
SHAOWEI HU
Keyword(s):  
Time History ◽  
Gravity Dam ◽  
Seismic Resistance ◽  
Size Difference ◽  
Crack Model ◽  
Gravity Dams ◽  
Dam Foundation ◽  
Failure Patterns ◽  
Shear Keys ◽  
Longitudinal Joints

In order to thoroughly study the seismic resistance of gravity dams with longitudinal joints, a contact model based on constraint function method is used to simulate the shear keys within the joints and a concrete smeared crack model is selected to present the cracking characteristics of concrete materials. Because of the great size difference between the shear keys and the dam body, a glue mesh is proposed to implement multi-scale modeling. A dam-foundation-reservoir interaction system with longitudinal joints considering the various shear keys is developed and analyzed by nonlinear time-history method. On the basis of actual construction, arrangement and loading features of shear keys, a gravity dam is taken as a test case and a finite element model of the dam is established with triangular or trapezoidal shear keys. The working behaviors and failure patterns of various shear keys under earthquakes are explored. Moreover, the effects of various shear keys on the seismic resistance of the gravity dam are discussed. The results show that the seismic responses of shear keys are resulted in designed forms. The occlusion and dislocation of the shear keys within the longitudinal joints have an impact on seismic resistance of the gravity dams.

scholarly journals Experimental Study of the Composition and Structure of Granular Media in the Shear Bands Based on the HHC-Granular Model

2014 ◽  
Vol 2014 ◽  
pp. 1-7
Author(s):  
Guang-jin Wang ◽  
Xiang-yun Kong ◽  
Chun-he Yang
Keyword(s):  
Shear Strength ◽  
Internal Friction ◽  
Granular Media ◽  
Random Distribution ◽  
Shear Bands ◽  
Friction Angle ◽  
Internal Friction Angle ◽  
Coarse Grained ◽  
Composition And Structure ◽  
Coarse Grained Soil

The researchers cannot control the composition and structure of coarse grained soil in the indoor experiment because the granular particles of different size have the characteristics of random distribution and no sorting. Therefore, on the basis of the laboratory tests with the coarse grained soil, the HHC-Granular model, which could simulate the no sorting and random distribution of different size particles in the coarse-grained soil, was developed by use of cellular automata method. Meanwhile, the triaxial numerical simulation experiments of coarse grained soil were finished with the different composition and structure soil, and the variation of shear strength was discussed. The results showed that the internal friction angle was likely to reduce with the increasing of gravel contents in the coarse-grained soil, but the mean internal friction angle significantly increased with the increment of gravel contents. It indicated that the gravel contents of shear bands were the major factor affecting the shear strength.

An Energy Approach to the Mechanics of Discontinuous Chip Formation

1964 ◽  
Vol 86 (2) ◽  
pp. 157-162 ◽  
Author(s):  
W. K. Luk ◽  
R. C. Brewer
Keyword(s):  
Shear Stress ◽  
Shear Strain ◽  
Normal Stress ◽  
Chip Formation ◽  
Strain Energy ◽  
Energy Condition ◽  
Stress And Strain ◽  
Rupture Plane ◽  
Shear Stress And Strain ◽  
Shear Strain Energy

After briefly reviewing previous work in this field, the authors propose that rupture of the chip work contact (to give a discontinuous chip) is governed by a limiting shear strain energy condition. Assuming that shear stress and strain at rupture are dependent on the compressive normal stress, a criterion for the direction of the rupture plane is deduced. Using some results given by Field and Merchant, the authors then compare their calculated direction of rupture with that experimentally observed. Some indication that the agreement is not entirely fortuitous is afforded by checking the calculated shear strain energy at fracture with that calculated from force and chip measurements.

scholarly journals Application of Probabilistic Method to Stability Analysis of Gravity Dam Foundation over Multiple Sliding Planes

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Gang Wang ◽  
Zhenyue Ma
Keyword(s):  
Probabilistic Method ◽  
Complex Problem ◽  
Probabilistic Methods ◽  
Gravity Dam ◽  
Engineering Profession ◽  
Concrete Gravity Dam ◽  
Dam Foundation ◽  
Performance Function ◽  
Probability Calculation ◽  
Implicit Performance Function

The current challenge to the engineering profession is to carry out probabilistic methods in practice. The design point method in generalized random space (DPG method) associated with the method of divided difference can be utilized to deal with the complex problem of probability calculation of implicit performance function with nonnormal and correlated variables. For a practical concrete gravity dam, the suggested method is performed to calculate the instability probability of the dam foundation over multiple sliding places. The general conclusions drawn in the paper are identical to those in other research and the method is proved to be feasible, accurate, and efficient. As the same analysis principle, the method can also be used in other similar fields, such as in fields of slopes, earth-rock dams, levees, and embankments.

Analysis on Seismic Behavior of Gravity Dam Based on ANSYS

2013 ◽  
Vol 353-356 ◽  
pp. 2159-2162
Author(s):  
Yan Bin Zhang ◽  
Fu Sheng Liu ◽  
Cong Lin ◽  
Lin Zhang
Keyword(s):  
Seismic Design ◽  
Seismic Behavior ◽  
Weak Link ◽  
Gravity Dam ◽  
Stress And Strain ◽  
Order Mode ◽  
Design Requirement ◽  
Finite Element Software ◽  
To Come ◽  
Square Root Method

Dynamic analysis can be carried out quickly and accurately for the seismic performance of dam by using the finite element software. Added massed method is used for the dynamic water. Horizontal earthquake acceleration is 0.2G; vertical earthquake acceleration is two-third of horizontal earthquake acceleration; sub space iteration method is used for the modal analysis of the dam; Finding the maximum response-order mode shape, and then useing a combination of square and square root method to come to the conclusion of overall seismic response. The stress and strain of the dam had been analyzed and the weak link of key parts of the dam had been summarized in this article.It is concluded that seismic design requirement are satified for the dam.

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