Advanced Materials Research Vols. 446-449

Abstract: This paper presents a new energy dissipation device for earthquake protection of structures. The proposed device, which uses a quasi-linear motion mechanism, achieves dissipation of seismic energy into the structure through yielding of U-shaped steel dampers. Consequently bracing members are subjected to only tensile force. Cyclic loading tests of the portal moment frames with the proposed device are conducted. Results and discussions are presented with emphasis on key features which affect energy dissipation capability. The lateral load and story drift angle relationships show that the proposed device provides stable and reasonably large energy dissipation capability. The effect of pre-tension applied to the bracing members is also examined through the brace axial strain and lateral load relationship.

Abstract: Based on the predecessors’ achievements and combined with the engineering project of Jinquan temple landslide located in Hanzhong city of Shanxi province, this paper takes international general geotechnical engineering professional analysis software—FLAC3D to do the numerical simulation. The deformation characteristics and mechanical properties of micropiles in lateral loads are researched. Working performance and load transfer rule of micropiles are analyzed. It is useful for the design of micropiles in 3 rows. It also has positive significance on the construction and design of micropiles reinforcing shallow landslide.

Abstract: Eutrophication is one of the most serious water quality problems in the world. Urban lake eutrophication evaluation with the aim of improving urban water environment quality will provide foundations for urban water environment management and remediation. Considering that lake eutrophication evaluation involves many indexes, many rankings and interval values, fuzzy variable sets theory is applied. Based on the premise that the same mathematics model is used, index weights are determined by means of entropy value method, equal weight method and pure threshold value method. Relative membership degree of each index belonging to each ranking can be calculated with relative difference function model. At last, the stability of feature values of classification corresponding to three methods is analyzed and grade of each sample is determined. This model is applied to Lake Dongchang. Three lake regions all belong to the fifth ranking, namely eutrophic. It basically corresponds to reality. So it can be indicated that the proposed model is reasonable and practical.

Abstract: Aimed to solve problems, such as deep soft soil foundation, strong wind and high wave and urgent construction period confronted in offshore dam construction, deepwater work ship has been researched and developed and further the construction and monitoring system has been innovated to break with traditional design and construction method, plastic drainage slab consolidation technology is to lead middle and low beach into offshore deepwater so as to quickly increase bearing capacity and settlement of the soft soil foundation and complete in construction period. This is characterized by security, reliability, economy and high efficiency.

Abstract: Based on the theory of damage finite element method, the deterioration process of hydraulic concrete under the freeze-thaw cycles is simulated. The damage evolution equation is deduced and freeze-thaw zone is discussed. The results indicate that the load capacity of structure is degraded under the freeze-thaw cycles. The deterioration of hydraulic concrete under the freeze-thaw cycles, however, is mainly limited at the region of the water fluctuation district and has a little effect to the overall structure. This means that the major loads causing hydraulic concrete failure under the freezing-thawing damage in the coldest region is not those of general design loads, such as gravity load and water pressure load, but the thermal loads, especially by the distinct daily temperature difference. Thus, the freeze-thaw modeling should consider these loads together.

Abstract: A numerical implement to simulate the crack propagating process in arch dam and rock base has been given. A new FE style was presented for improving the calculation accuracy and efficiency. In the period of dividing the dam structure and the foundation rock into an appropriate number of discrete subregion (finite elements), the adaptive method was used to divide the original 3-D element into a serial son-elements analogical to its father-elements entirely. Of course the 2-D element was divided into a serial son-elements analogical to its father-elements entirely using the same method. The element shape function was key factor. In the calculating processor, the arithmetic of load step was optimized. The arithmetic has important theory and utility value

Abstract: On the basis of summarizing over years’ promotion and application of four-side and six-edge permeable frame group river control, bank protection and erosion control technology, analyse and discuss the issues of promotion and application. Discuss the applicative scope and conditions of this technology, propose the design principles and methods of permeable component group geometric dimension, and analyse the feasibility of building Permeable-Entity and Rigidity-Flexibility compound protection engineering.

Abstract: Effective numerical technique for treatment of inclined boundary in the finite element method was introduced. Finite element method was frequently used to analyze hydraulic phenomena in the coastal zone because it can be applied to irregular and complex geometry. In this study, we introduced the way to treat the boundary condition over an inclined bottom.

Abstract: Through project examples, this paper set up a two-dimensional finite element seepage flow model with the help of the Auto-BANK software, to solve the soakage line overflow points, seepage quantity and seepage gradient of the earth dam based on the basic equation of steady seepage flow of earth dam and definite conditions. It is found that this method can effectively calculate and analyse multi-media seepage flow field with complex boundaries.

Abstract: The water resources is a complex coupling system,combined with the human social development and living environment. Water resources optimal allocation plays an important role in supporting the whole sustainable development of national economy in Weinan city as the solution about the shortage of urban water resources .In this paper, we take the urban water supply and the water resources system in Weinan city as the research object, through the analysis of the actual data, analyzing the elements and relationships between systems of urban water supply in Weinan city and the characteristics of the water resources project, adopting optimization theory of dynamic programming principle to build the Weinan city water resources optimization allocation model, and puts forward the method of benefit function to obtain the strategy plan for optimal allocation of water resources in the city.