Journal of Water Resources Science and Technology No.27
Create date: 06/26/15


WATER RESOURCES SCIENCE AND TECHNOLOGY JOURNAL
No 27 (June/2015)

No

Article

Author

Summary

I

SCIENCE TECHNOLOGY

 

 

1

The process of formation and development of vertical breach of multi block rockfill dam

Assoc.Prof. Nghi, Le Van

Eng. Huu, Bui Van

Eng. Thanh, Pham Hong

Determination the breach characteristics is the most difficult problem in dams failures calculating. Breach characteristics include: Breach width; height of vertical breach; failure time, outflow… The article presented experimental results on physical model of process of formation and development of vertical breach with prototype is the main dam of Hoa Binh hydropower.

2

Impacts of the Rach Gia - Kien Giang sea dike on saline intrusion in the Mekong Delta

Dr. Quynh, Nguyen Phu

MSc. Vinh, Pham The

Assoc.Prof. Hoa, Vu Hoang

The Mekong Delta coastal zone is experiencing increasing drought, water shortage and salinity intrusion into the mainland. Rach Gia Bay sea dike is being proposed by Ministry of Science and Technology to create a large fresh water reservoir to supplement fresh water for the region in dry season, as well as to create large land area for agriculture, tourism development  etc. ...

Initial study results showed that, one-way operation of sluice gates during a flood season could help make fresh water in a reservoir of 820 million-m³ capacity. In the case of keeping sluice gates opened throughout flood season and closed gate  throughout dry season, the area ofRach Gia bay mouth could become fresh, while areas from the mid-bay tothedike alignment thesalinityis maintained from1.8 to 2.4g/l.

3

Vietnam Women's Union with the increasing provision for social capital for rural women in New Rural Development Program

Dr. Hoai, Nguyen Thi Thu

MSc. Trung, Pham Chi

Social capital is a non-economic resource which very clearly exists in rural communities. In the context of building new rural, social capital has the role of promoting and metabolism of other resources such as human capital and financial capital, ... into powerful resources for building new rural. In the network of social and political organizations in rural areas, Women's Union and Farmers Union are two organizations which attract more participants and have an active role in implementing  undertakings and policies of governmental comes to life. With this paper, the author wants to demonstrate in detail of the role of the Vietnamese Women's Union in social capital mobilization in new rural construction from the investigation in the research project of Research on solutions of Social capital mobilization for development of non-agricultural sectors in new rural construction of Science and Technology Program for building new rural in the 2012-2015.

4

Performance analysis of relay system to protect small-power generator during black start-up

Dr. Tung, Nguyen Xuan

Dr. Huy, Nguyen Duc

Dr. Viet, Nguyen Xuan Hoang

MSc. Hung, Le Viet

MSc. Nga, Ngo Thi Thanh

MSc. Anh, Vu Tuan

Eng. Du, Hoang Minh

This paper introduces analysis results regarding the operation of protective relaying system of small generator during black start process; network is being in an islanding state. During islanding operation, the short circuit capacity of source may reduce significantly and it may lead to reduction in sensitivity of protective relay systems. The paper focuses on impact of islanding operation mode to the operation of relay protection system for small generator and proposes solutions in order to overcome those drawbacks. The results of analysis are applied to investigate the relay protection system of small generators at Suoi Tan hydro power plant with various black starting scenarios.

5

Some measures to improve the performance of Trung Thanh environmental & sanitation service cooperative

Assoc.Prof. Huong, Vu Thi Thanh

MSc. Chinh, Vu Quoc

Cu, Le Van

The service organizations for rural waste management have been formed spontaneously and their activities are mainly based on collecting fee of housholds so that leading to inefficient operation and unsustainability. This article is dealing with the application of some measures to improve the operational efficiency of the service provider,Trung Thanh Cooperative forenvironmental sanitation in Pho Yen district, Thai Nguyen province. This model showing the operational sustainability, contributes for the environmental improvement and enhancing the community’s awareness. The implementation results are the foundation to propose support policies for developing the services organizations for rural environment.6

6

Analysis of the actual consolidation coefficient of weak soils from field observations

Dr. Vinh, Le Ba

Coefficient of horizontal consolidation (Ch) is a very important parameter to predict the speed of settlement of soft ground improved by preloading method combined with surcharge. In the designs coefficient of horizontal consolidation is often calculated by coefficient of vertical consolidation with a factor. This can lead to the calculated results with different values. In this paper, by using results of the field experiments such as CPTu, piezometer test, ... as well as the back analyses of the actual monitoring settlement, the actual value of coefficient of horizontal consolidation is analyzed, evaluated by different methods. Also, the difference between the coefficient of horizontal consolidation of the ground in-situ and the coefficient of vertical consolidation in laboratory is obtained.

7

Study for energy dissipater of  Piano type A weir (n = 4.3)

Dr. Hien, Truong Chi

Experimental studyon physical modeling to determine the discharge capacity of the P.K. weirs Types A (N = 4.3) and the dimension of stilling basin in the hydraulic structures. This research was performed for the hydraulic head ranged from 20 to 25 m for selected dimensionless relationships between the design parameters.

The experimental results will provide the hydraulic characteristics of the P.K. weirs Types A in the free flow and the dimension of stilling basin. These will contribute to select the appropriate type for the design and construction projects.

8

The analytical method  for calculation of the irrigation coefficient for rice from the sequent irrigation point of view

Dr. Sach, Bui Nam

In view of rotation irrigation, this means water is supplied whenever sowing preparation happens. After water is supplied to fields, water loss occurs including free evaporation, permeation to saturation level, stable permeation, evapotranspiration, and water level raising and lowering on fields.

Analysis is done for each process of water loss by estimating the amount of daily water loss throughout the whole process for each plot. Adding up water loss of each plot in the same period makes the total water loss in each irrigation district. Therefore, the formula of water loss for each period is established based on analysis of total water loss of each irrigation district. The formula of other water loss processes is established in a similar method. Finally, the summation of constituent water loss line makes the general water loss line of the irrigation district. Taking into account the general water loss of the irrigation district, the required water level on fields, and inflow, the trial and error method is applied to find out the irrigation amount mi and then estimate the irrigation coefficient. For rotation irrigation, this calculation method helps estimating irrigation coefficient in a faster, easier, and more convenient manner.

9

Analyze and appraise the effectiveness of some spur dikes in the Red River System

Dr. Quyet, Nguyen Kien

In Northern River Delta system, works act on major flows to be spur dike, special in Red River system have many spur dike  was built in  either right or left Red River bank. Built works have little effect, and also have some remains. In contents of paper, author only analyses limitations and existences in some spur dike works system, to promote withdraw experiences in river training field by works act on flows in Vietnam. 

10

Analyzing the effect of the ideal PVDs and not ideal PVDs in the simulation of floor treatment by vacuum method combined with PVD for weak soil foundation

Dr. Vinh, Le Ba

This paper introduces the analysis of simulation methods of vacuum preloading combined with PVD to improve a soft ground. The simulation methods of ideal PVDs and not ideal PVDs were done with two actual projects. The obtained results of settlement, horizontal displacement, excess pore water pressure were compared with the actual monitoring results. Therefore, depending on the conditions of vacuum technology and experience of the contractor to determine how to simulate the drains to correctly estimate the final settlement as well as other behaviors of the ground.

 

Science and technology information and activities

 

 

 

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