Construction Of Hydropower Projects Research Articles

Hydro-torrential hazard vs. anthropogenic activities along the Seti valley, Kaski, Nepal: Assessment and recommendations from a risk perspective

The Seti River originates from the Annapurna Massif in the Higher Himalaya of Nepal and flows through the Pokhara valley in the Lesser Himalaya. The Seti River witnessed a disastrous flash flood on May 5th, 2012 causing the death of 72 people, obliterating dozens of homes and damaging infrastructures worth millions of dollars. Despite the 2012 flood event and several warnings by scientists for more yet bigger scale future floods in the Seti valley, fluvial risk is being aggravated by anthropogenic activities such as unplanned human settlement, encroachment of riverbanks, haphazard construction of road, drinking water, and hydropower projects in potential flood hazard areas in addition to the increased impacts of climate change on geological and hydro-metrological hazards as in other parts of Hindu Kush Himalayan Range. Covering some 40-km distance from the Seti headwater (Sabche Cirque) down to Pokhara city, the study is carried out based on hydro-geomorphological mapping, analysis of land-use and land-cover change, hydrological analysis including HEC-RAS modelling, historical archives, and interviews with local people. The study shows a significant change on the land use and land cover of the Seti catchment, mainly the urban/built-up area, which is increased by 405% in 24 years period (1996 to 2020) and by 47% in 7 years period (2013 to 2020). Further the study reveals that anthropogenic activities along the Seti valley have increased fluvial risk and are likely to invite more disasters. From the HEC-RAS analysis, two motor bridges built over Seti River were found to have insufficient freeboard to safely pass the highest flood discharge for 100 years return-period. Instead of relocating people to safer places, the government and local authorities rather seem to have encouraged people to live in the floodplain by providing basic amenities such as drinking water, electricity and access road. Given the context of climate change and Pokhara valley and the Seti catchment being in a high-seismic gap zone, there is a strong possibility of similar flood to the scale of 2012 or even greater in Seti River. Though the fluvial risk can be managed in a sustainable way through the application of functional space concept, i.e., by allowing more space (freedom) for rivers, this economic and environment friendly approach of the fluvial risk management has not been implemented yet in the Seti valley nor in Nepal. Rather the encroachment of floodplains by anthropogenic activities along the Seti valley is on an increasing trend. Many settlements and infrastructures along the valley have been identified vulnerable to hydro-torrential hazards, therefore it is utmost necessity to implement functional space river concept, land use and land plan policy, early warning system and public awareness education in order to mitigate and manage the future impact of fluvial hazards along the Seti valley.

Mechanical properties, durability, and ITZ characteristics of full-grade dam concrete prepared by aggregates with surface rust stains

Aggregates with surface rust stains (ASRS) is very common in the construction of water conservancy and hydropower projects. The purpose of this paper is to provide the possibility to utilize rusted raw rocks as aggregate in dam concrete. The physical and chemical properties of rusted raw rocks are measured. In addition, comparisons of their mechanics and the durability of dam concrete prepared by ASRS and rust-free limestone aggregates (RFLA) are investigated. The characteristics of interfacial transition zone (ITZ) between aggregate and paste are investigated by the means of scanning electron microscope with energy dispersive spectrum (SEM-EDS) and nano-indentation technology. The results show the apparent density and uniaxial compressive strength of ASRS are lower than the RFLA by 10 kg/m3 and 5.3 MPa, respectively. The compressive strengths of ASRS concrete are approximate those of RFLA concrete. The tensile strength of ASRS concrete is lower than that of RFLA concrete by 13 %. The ASRS slightly reduces the dam concrete frost resistance and impermeability. The ITZ average thickness of the ASRS sample is thicker than that of the RFLA sample by 15.0–20.0 μm. The values of indentation modulus and hardness observed across the ITZ in the ASRS sample are lower than those of the RFLA sample by 6.31 GPa and 0.11 GPa, respectively. The ASRS can be utilized as aggregates in dam concrete, such as in the structure with lower tensile strength requirements.

Discussion on the Prevention and Control of Concrete Cracks in the Construction of Water Conservancy and Hydropower Projects

Discussion on the Prevention and Control of Concrete Cracks in the Construction of Water Conservancy and Hydropower Projects

Research on Hazard Source Identification and Prevention and Control Countermeasures of Water Conservancy and Hydropower Project Construction Site

Research on Hazard Source Identification and Prevention and Control Countermeasures of Water Conservancy and Hydropower Project Construction Site

Implementation of BIM + WebGIS Based on Extended IFC and Batched 3D Tiles Data: An Application in RCC Gravity Dam for Republication of Design Change Model

The construction of hydropower project is a complex management process, whose management covers the entire construction site. Building information modeling (BIM) + Web Geographic Information System (WebGIS) is an effective means to solve the management of the construction site and main structures. Industry foundation classes (IFC) is commonly used in architecture, engineering and construction (AEC) industry as a standard for BIM data exchange. However, as the components of hydropower projects have not been included in IFC standards, IFC needs to be extended in application. At the same time, WebGIS pays more attention to display whole scene and ignores the processing of high-precision models. There will be deficiencies in network transmission and browser rendering in WebGIS environment of elaborate BIM model. Therefore, the batched three dimensions (3D) Tiles data format, which uses Web Graphics Library (WebGL) as the standard for 3D model rendering, has been widely considered in recent years. At present, in the field of BIM and GIS fusion, the conversion of extended IFC to 3D Tiles data is still blank, and none of the current BIM modeling software has the ability to export the components of hydropower projects. This paper proposes an extended IFC export method based on Autodesk Revit and a data exchange from extended IFC to batched 3D Tiles. Finally, the effectiveness of this method is verified by a design modification case of roller compacted concrete (RCC) gravity dam.

Study on automatic welding technology of single-side welding and double-side forming of large diameter steel

The installation of penstocks in the construction of water conservancy and hydropower projects should be a key link in the quality control of hydropower projects. It is of great significance to the stability and safety of hydropower projects. Based on the construction process requirements of the steel pipe in the tunnel of a water conservancy project in South China, this paper has developed an all-position automatic welding technology of single-sided welding and double-sided forming of the inner circumferential seam of a super large diameter steel pipe after many tests, and analyzed the factors affecting the welding quality. After repeated trials and adjustments of process parameters, a lower welding voltage (small molten pool) and a larger welding current (guaranteed penetration) are used to ensure a certain deposition efficiency, and finally stable welding quality is achieved. It has certain reference significance for the improvement and improvement of the automatic welding technology of single-side welding and double-side forming of large-diameter steel pipes.

Research on Water Conservancy and Hydropower Project Management and Construction Quality Control

Research on Water Conservancy and Hydropower Project Management and Construction Quality Control

Calculation of Filling Ratio of Fissures for Curtain Grouting by Acoustic Velocity of Rock Masses

In the construction of hydropower projects, the detection method for curtain grouting has not been recognized for the filling the fissures at present. This paper calculates the filling ratio of fissures in rock masses using acoustic velocity data before and after grouting. According to a simplified two-phase model of rock mass, a calculation formula of filling ratio for rock mass fissures is derived from acoustic velocity. The rock mass velocity ratio curve before grouting is fitted according to Poisson distribution formula to obtain the rock mass velocity, and then the filling ratio for rock mass fissure grouting is calculated by combining water, cement, rock mass velocity before and after grouting. The filling ratio of fissures in the rock mass after curtain grouting by using the acoustic velocity of the rock mass in a hydropower project can be mutually verified by the results of the borehole TV and water pressure test.

Research on construction safety Evaluation and management system of water conservancy and hydropower projects

Along with our country economy sustained and stable growth, water resources and hydropower engineering industry development is rapid, a fairly long period of time in the future will be in the process of engineering construction, however, with the rapid development of water resources and hydropower engineering industries came the frequent safety accidents of water resources and hydropower engineering construction, cause huge casualties and property losses, and has a great influence on society. On the surface, most of the safety accidents are caused by improper human operation or mechanical equipment injury, but at the root of the problem, most of the accidents are caused by potential accidents in safety management. Therefore, how to improve the safety management level of water conservancy and hydropower project construction, improve the level of construction safety management information is the current urgent task of water conservancy and hydropower project construction enterprises.

Study of the in situ stress field in a deep valley and its influence on rock slope stability in Southwest China

The in situ stress field in valley areas is an important factor to consider in the construction of hydropower projects in southwest China. Due to intense tectonic movement, the action of gravity, and rapid river erosion, the resulting stress has a complex distribution and a large magnitude. The availability of stress measurements is insufficient to provide adequate understanding of the regional stress state. In this research, inversion analysis for the in situ stress field of a valley in the upper reaches of the Lancang River is carried out by using stepwise regression analysis and the FLAC3D numerical simulation, and the temporal and spatial distribution characteristics of the in situ stress are obtained. Based on those results, the influence of stress unloading effects on slope stability is discussed. The results show that the formation of the modern in situ stress field is the comprehensive result of interactions among gravity, tectonic movement, and river erosion. The reliability of the inverse result can be increased by improving the mesh density of the calculated model and considering multistep river erosion. Under the influence of the unloading effects, tensile fractures were formed and the rock mass loosened near the slope surface. With the presence of bedding dipping into the slope, toppling failure was triggered by the unloading rebound that mainly occurred in the stress relaxation zone.

An analysis of causes of delay and cost overrun in construction of hydropower project

This research precisely analyzes the delay causes of one of the most delayed hydropower project in Pakistan. In this study, grey relation analysis has been employed which has strong analytical ability, in the process of grey relational analysis calculation, the same weight cannot fully reflect the optimality of evaluation, so we have used the entropy weight method to improve it, at the same time, we have used full information reflected by the evaluation index. The socioeconomic problems which are delaying this project (Diamar‐Basha dam) which include poor resettlement plan for local people, compensation of land, threat of cultural heritage, and ecological impacts of this project. It gives quantitative analysis by taking into account several issues in infrastructural project activities like historical and geographical disputes between local people and Governments, their socioeconomic impacts on affected population due to lack of finance and land use conflicts. The deeper roots behind the excusable delays of construction of the Diamar‐Basha dam are discovered in its true spirit while the putative reasons are decorated how this project get into such a predicament and further delay in construction of dam will make it a mirage project.

A COMBINED EXPERIMENT-SIMULATION STUDY ON TEMPERATURE REGIME OF ROLLER-COMPACTED CONCRETE APPLYING FOR DAM CONSTRUCTION

Similar to most of the other developing countries, Vietnam has national programs for industrial waste recycling including fuel, ash, and slag. In which, fly ash (FA) has been used commonly as a pozzolanic additive in the roller-compacted concrete (RCC) mixture for the dam construction of hydropower projects. This usage allows reducing the concrete cost, the hydration heat, and the thermal cracking during the construction process of the RCC. In this study, the optimal concrete mixture and the maximum temperature of the RCC dam were determined using the experiment planning method, Matlab, Maple 13, and Midas Civil. In addition, the mathematical model has been used to adequately describe the influence of the intensity concreting (IC) and the initial temperature of the concrete mixture (ITC) on the temperature regime of the RCC dam. The calculation of the temperature regime during the construction of the RCC dam of 45 m high and 1 m thick in Vietnamese climate conditions was performed with considering the IC and the ITC. As the results, the maximum temperature of the RCC dam was determined depending on the IC and the ITC. Calculation found that at IC = 0.6 m/day and ITC = 20°C, the maximum temperature in the central dam zone reached 36.38°C after 1800 hours from the beginning of construction. The results of the present study further support the safe and durable construction of the RCC dam in the future.

Assessment of Environmental Changes using GIS Applications

Hydropower is one of the prominent sources of electricity and renewable. It is also one of the key sources of economic growth for the Himachal Pradesh state. With the idea of an increase in hydropower projects increase the economy, the state is building more hydropower projects. The construction of hydropower projects has a significant impact on the environment both positive and negative. This work focuses on assessing the environmental changes in the Pandoh hydropower project’s basin in terms of sufficiency of the environmental flow for the sustenance of agriculture’s health and vegetation. Pandoh hydropower project was established in 1977 in the Mandi District, Himachal Pradesh producing up to 990 MW. It is situated along the downstream side of the Larji hydropower project and sources of water are the releases from the Larji reservoir. It is also a source for the Dehar hydropower project downstream to the Pandoh dam. The assessment has been done using the Normalized Difference Vegetation Index and Land Use Land Cover Change. The analysis is carried out for two periods, healthy (August to October) and lean period (November to February), that too before and after the construction of the dam. The results show that the impact prevails in the study area with a decrease in agricultural land and an increase in urbanization.

Exploration and practice of intelligent engineering in Dadu River hydropower construction

Abstract In view of the difficulties in promoting intelligent management in the field of engineering construction, based on the concept of intelligent enterprise and the actual situation of hydropower project-construction management, this paper puts forward the basic concept, main features and general idea of intelligent engineering. Based on a review of the exploration, pilot construction and comprehensive practice of intelligent engineering in the hydropower construction of Dadu River, the practical results of the intelligent engineering of Dagangshan, Houziyan, Shaping-II and Shuangjiangkou hydropower stations are summarized. The technical system and management model of engineering an early-warning decision centre, intelligent dam project, intelligent underground project, intelligent electromechanical project, intelligent security control, intelligent service guarantee, intelligent environmental and water protection, and intelligent resource control in Shuangjiangkou hydropower station are introduced. It is proposed that intelligent engineering is a high integration of information technology, industrial technology and management technology. And it is pointed out that intelligent engineering will lead in the new development of water conservancy and the hydropower industry, and even the engineering-construction field, throughout the world.

Research on Treatment Methods and Pollution Control of Construction Wastewater in Hydropower Construction Projects

Hydropower construction projects have the characteristics of large construction scale, short construction period, large wastewater discharge and difficult management, and the waters near hydropower stations may be close to environmentally sensitive areas such as scenic spots and historic sites and forest reserves. If construction wastewater is not treated and discharged, it will have great impact on the environment. Based on the engineering analysis of hydropower construction projects, this paper understands that the construction waste water mainly consists of stone aggregate washing waste water and concrete mixing system washing waste water. According to the principle of coagulation and sedimentation and the characteristics of engineering waste water, the construction waste water is treated by physical and chemical methods and combined with coagulation and sedimentation process, so as to reduce or eliminate negative environmental impact, avoid environmental risks and control pollution.

AGRICULTURAL PRODUCTION OF CA DONG PEOPLE IN RESETTLEMENT AREA OF TRANH RIVER HYDROPOWER NUMBER 2: CURRENT SITUATION AND IMPACT FACTORS

In Vietnam, the construction of hydropower projects has contributed significantly in the cause of industrialization and modernization of the country. The place where hydropower projects are built is mostly inhabited by ethnic minorities - communities that rely primarily on land, a very important source of livelihood security. In the context of the lack of common productive land in resettlement areas, the orientation for agricultural production is to promote indigenous knowledge combined with increasing scientific and technical application; shifting from small-scale production practices to large-scale commodity production. However, the research results of this article show that many obstacles in the transition process are being posed such as limitations on natural resources, traditional production thinking or the suitability and effectiveness of scientific - technical application models. When agricultural production does not ensure food security, a number of implications for people’s lives are increasingly evident, such as poverty, preserving cultural identity, social relations and resource protection. Since then, it has set the role of the State in researching and building appropriate agricultural production models to exploit local strengths and ensure sustainability.

Novel Probabilistic Cost Estimation Model Integrating Risk Allocation and Claim in Hydropower Project

AbstractThe uncertain construction of hydropower projects and fierce market competition put forward more stringent requirements for contractors with regard to accuracy and competitiveness of cost e...

Impact and Evaluation of Construction Stage of Water Resources and Hydropower Projects on Ecological Environment

With the continuous development and progress of modern society, engineering construction in various fields is also constantly improved. Among them, water conservancy and hydropower engineering are the main guarantee project for the development of modern society. However, large area of earthwork needs to be constructed in the construction process of water conservancy and hydropower engineering. In order to effectively solve the impact of water conservancy and hydropower engineering on the ecological environment in the construction process, in order to promote the construction of water conservancy and hydropower projects and provide a good impetus for the work of ecological environment protection, it is necessary to analyze and study the actual impact and formulate scientific and reasonable solutions. Based on this, this paper will analyze the impact of water conservancy and hydropower projects on the ecological environment, and then work out the construction of water conservancy and hydropower projects and ecological environment protection measures, and finally provide a good guarantee for the smooth construction of water conservancy and hydropower projects and the protection of the ecological environment.

Integrating and managing BIM in 3D web-based GIS for hydraulic and hydropower engineering projects

Hydraulic and hydropower engineering projects are characterized by large scale, long construction period, complicated technology, high professional requirements, complicated management, and difficult coordination and cooperation. Due to the complex nature of these projects, the combination of a digital representation of physical and functional properties with geospatial information will yield a more reasonable solution. Hence, this study aims at the development of an integrated method and the BIM/GIS Integration Platform (BGIP) for implementing the micro- and macro-information into a unified environment without the need to convert standards or to install plug-ins. In this paper, an integrated methodology and a customized model are proposed for addressing differences in geometric visualization and coordinating transformation based on IFC formats, a rendering technique and a 4 × 4 transformation matrix. A prototype application, namely, the BIM/GIS integration platform (BGIP), is designed to serve as a testbed and is used to build a new construction tool for hydropower project construction. Finally, the feasibility and practicality of the proposed method are evaluated using a typical representative case in hydraulic engineering. The new approach offers a satisfactory scheme for resolving the inconsistencies in the storage, accuracy and operational speed of the model for combining BIM model information and GIS geospatial information.

Numerical Analysis and Deformation Mechanism Study on an Excavated High‐Steep Slope of a Hydropower Station

The high‐steep rock slope stability is one of the key technologies in the construction of water conservancy and hydropower projects, which affects and restricts the development of hydraulic resources and the construction of hydropower projects. In this paper, a three‐dimensional numerical model was built incorporating stratigraphy, geological structures, and the inverted rock mechanical parameters to perform displacement, stress, and plastic zone analyses for an excavated slope in China using the FLAC3D software. The numerical simulation results after slope excavation show that the deformation near the fault fracture zone is the largest, ranging from 350 mm to 380 mm. The compressive stress is concentrated on the slope foot and the connecting part, the stress value is 2 MPa∼5 MPa, there is a large tensile stress area in the slope, and the tensile stress value is 0 MPa∼0.4 MPa. The plastic zone of the slope is concentrated near the fault F6 and the structural influence zone, and the rock mass of the slope basically enters the plastic state. On this basis, the deformation mechanism of slope was analyzed, while the internal and external factors affecting the slope deformation were described in detail. This work would provide an effective reference basis for slope stability evaluation and treatment of similar hydropower stations.