Overview

The Shiyazi Dam is a concrete gravity dam located on the Hongjiadu River, a tributary of the Wu River, in Wuchuan County, Guizhou Province, China. The facility serves primarily for hydroelectric power generation and features an installed capacity of 140 MW. The dam structure stands 134.5 m tall and withholds a reservoir with a capacity of 321,500,000 m3. Construction utilized both normal concrete and roller-compacted concrete to manage the engineering challenges of the site.

Construction on the Shiyazi Dam began in 2007, with concrete pouring commencing in April 2008. The reservoir began to impound water in September 2010, marking a key phase in the project's timeline. The dam was "capped off" with concrete on 24 December 2011, and the generators were commissioned a week later on 31 December 2011. The facility is currently operational.

The dam is situated in a steep portion of Meilin Canyon, which presented significant difficulties during construction. The power station is located 320 m downstream from the main dam structure. It contains two 70 MW Francis turbine-generators, which together provide the total installed capacity of 140 MW. The operator of the facility is.

Geography and Site Conditions

The Shiyazi Dam is located in Wuchuan County, Guizhou Province, China. It is situated on the Hongjiadu River, which serves as a tributary of the larger Wu River system. The specific site is characterized by its placement within Meilin Canyon, a topographically challenging area defined by steep valley walls. This geographical setting presented significant construction difficulties for the engineering teams. The dam structure is a concrete gravity type, designed to withstand the hydraulic pressures of the reservoir while integrating with the rugged canyon environment. The power station associated with the dam is positioned 320 m (1,050 ft) downstream from the main dam structure, optimizing the head for energy generation.

Physical Dimensions and Reservoir Characteristics

The Shiyazi Dam stands 134.5 m (441 ft) tall. The construction utilized a combination of normal concrete and roller-compacted concrete (RCC) to form the gravity structure. The reservoir created by the dam has a total capacity of 321,500,000 m³ (260,644 acre⋅ft). These dimensions are critical for the hydroelectric power generation purpose of the facility. The following table summarizes the key physical and geographic parameters of the Shiyazi Dam project.

Parameter Value
Location Wuchuan County, Guizhou Province, China
River Hongjiadu River (Tributary of the Wu River)
Canyon Meilin Canyon
Dam Height 134.5 m (441 ft)
Dam Type Concrete Gravity
Reservoir Capacity 321,500,000 m³ (260,644 acre⋅ft)
Power Station Location 320 m (1,050 ft) downstream

Construction History and Timeline

The construction of the Shiyazi Dam was characterized by significant logistical challenges due to its location in the steep terrain of Meilin Canyon. The project, situated on the Hongjiadu River in Wuchuan County, Guizhou Province, required careful engineering to manage the concrete gravity structure in such a rugged environment. Construction activities officially commenced in 2007, marking the beginning of the physical development of the hydroelectric facility. The project progressed to the critical concrete pouring phase in April 2008, establishing the foundational and structural integrity of the dam.

The dam utilizes a combination of normal concrete and roller-compacted concrete to achieve its final height of 134.5 meters. This dual-concrete approach was essential for managing the structural demands of the 134.5 m tall gravity dam. Following the structural completion, the reservoir began to impound water in September 2010, initiating the filling process for the 321,500,000 m3 capacity reservoir. The dam was officially "capped off" with concrete on 24 December 2011, signaling the near-completion of the civil works. The generators were commissioned one week later on 31 December 2011, bringing the two 70 MW Francis turbine-generators online for a total installed capacity of 140 MW.

Construction Timeline

Year Event
2007 Construction on the Shiyazi Dam began.
April 2008 Concrete pouring commenced.
September 2010 The reservoir began to impound water.
24 December 2011 The dam was "capped off" with concrete.
31 December 2011 Generators were commissioned.

Engineering Design and Materials

The Shiyazi Dam is engineered as a concrete gravity dam, a structural design that relies primarily on the dam's own weight to resist the horizontal pressure of the water. This type of structure is particularly suited to the site's geological conditions, providing stability through mass rather than arching action. The dam reaches a height of 134.5 m (441 ft), a significant vertical scale that necessitated robust material selection and construction methodologies. The construction utilized a combination of normal concrete and roller-compacted concrete (RCC). This hybrid approach leverages the distinct advantages of both materials. Normal concrete provides high compressive strength and durability for critical structural zones, while roller-compacted concrete offers faster placement rates and reduced thermal cracking potential, which is crucial for large-volume pours. The integration of RCC allowed for efficient progress during the concrete pouring phase, which commenced in April 2008. Engineering challenges were significant due to the dam's location within a steep portion of Meilin Canyon. The rugged terrain complicated access, material transport, and formwork erection. Constructing a 134.5 m high structure in such a confined, vertical landscape required precise logistical planning to manage the flow of aggregates, cement, and water to the construction face. The difficulty of the site is noted as a primary factor in the project's complexity. The reservoir created by the dam has a total capacity of 321,500,000 m3 (260,644 acre⋅ft). This volume is managed by the gravity structure, which withholds the water to create the necessary head for power generation. The power station is situated 320 m (1,050 ft) downstream from the dam crest. This separation allows for the use of penstocks to channel water to the turbines, optimizing the hydraulic head and allowing for a more flexible layout of the generating equipment. The station houses two 70 MW Francis turbine-generators, contributing to the total installed capacity of 140 MW. The construction timeline reflects the complexity of the engineering tasks. Work began in 2007, with concrete pouring starting in April 2008. The reservoir began to impound water in September 2010. The dam was structurally completed, or "capped off," on 24 December 2011. Commissioning of the generators followed shortly after, on 31 December 2011, marking the operational readiness of the facility.

Hydroelectric Power Station Specifications

The Shiyazi hydroelectric power station is situated 320 m (1,050 ft) downstream from the main concrete gravity dam structure. This spatial separation allows for a significant hydraulic head to drive the turbine-generators, optimizing energy extraction from the impounded waters of the Hongjiadu River. The power house contains two identical generator units, each rated at 70 MW, resulting in a total installed capacity of 140 MW for the facility. These units utilize Francis turbine technology, a choice well-suited for the medium-head conditions typical of mountainous river systems like the Wu River tributary network in Guizhou Province.

Turbine and Generator Configuration

The installation of two 70 MW Francis turbine-generators provides operational flexibility, allowing the plant to adjust output based on seasonal water flow variations and grid demand. The Francis turbine is a reaction turbine that combines radial and axial flow concepts, making it one of the most efficient and widely used turbine types for hydroelectric power generation in the 140 MW capacity range. The specific selection of this technology for the Shiyazi project reflects the engineering requirements of the Meilin Canyon location, where the steep terrain facilitates the necessary drop in elevation between the reservoir and the downstream power station.

Operational Timeline and Commissioning

This rapid sequence of events highlights the efficiency of the construction phase, which had begun in 2007 with concrete pouring starting in April 2008. The reservoir began to impound water in September 2010, providing the initial hydraulic pressure needed for the preliminary testing and subsequent full commissioning of the two 70 MW units. The operational status of the plant remains active, contributing to the regional energy infrastructure of Wuchuan County.

What are the technical specifications of Shiyazi Dam?

The facility is primarily designed for hydroelectric power generation. Construction activities commenced in 2007, with concrete pouring operations beginning in April 2008. The reservoir started impounding water in September 2010. The location within the steep terrain of Meilin Canyon presented significant construction challenges.

Structural Specifications

It is constructed using a combination of normal concrete and roller-compacted concrete.

Hydropower Plant Details

It contains two Francis turbine-generators, each with a capacity of 70 MW. This configuration provides an installed capacity of 140 MW.

Parameter Value
Entity Type Hydroelectric Power Plant
Country China (CN)
Province Guizhou
County Wuchuan
River Hongjiadu River (tributary of Wu River)
Dam Type Concrete Gravity
Dam Height 134.5 m (441 ft)
Construction Material Normal Concrete, Roller-Compacted Concrete
Reservoir Capacity 321,500,000 m³ (260,644 acre⋅ft)
Power Station Location 320 m (1,050 ft) downstream
Turbine Type Francis
Number of Generators 2
Individual Generator Capacity 70 MW
Total Installed Capacity 140 MW
Construction Start 2007
Concrete Pouring Start April 2008
Reservoir Impoundment September 2010
Dam Capping 24 December 2011
Commissioning 31 December 2011
Operational Status Operational

Why it matters

The Shiyazi Dam represents a significant engineering and energy infrastructure achievement within Guizhou Province, China. As a concrete gravity dam with an installed capacity of 140 MW, it plays a distinct role in the regional hydroelectric portfolio, specifically contributing to the development of the Wu River basin. The facility is situated on the Hongjiadu River, a tributary of the Wu River, in Wuchuan County. Its construction and operation reflect the strategic expansion of hydropower in this geographically complex region, leveraging the natural topography to generate renewable energy.

Engineering in Meilin Canyon

The construction of the Shiyazi Dam was notably challenging due to its location in a steep portion of Meilin Canyon. The dam stands 134.5 m (441 ft) tall and was built using a combination of normal concrete and roller-compacted concrete. The reservoir began to impound water in September 2010. The use of roller-compacted concrete alongside normal concrete highlights the engineering adaptations required to manage the steep canyon terrain and ensure structural integrity.

Role in the Wu River Basin

Shiyazi Dam contributes to the hydroelectric development of the Wu River tributaries. The power station is located 320 m (1,050 ft) downstream from the dam and contains two 70 MW Francis turbine-generators. This configuration provides a stable source of hydroelectric power for the region. The facility is currently operational, having been commissioned in 2011. Its operation supports the energy infrastructure of Guizhou Province, adding to the province's status as a major hydropower producer in China. The dam's design and location allow for efficient water management and power generation in the Wu River system.

Frequently asked questions

When was Shiyazi Dam completed and commissioned?

Following this structural milestone, the power station's generators were commissioned one week later, on 31 December 2011. Therefore, the facility reached operational status at the very end of 2011.

What type of turbines are used at Shiyazi Dam?

The Shiyazi Dam power station utilizes two Francis turbine-generators. Each of these turbines has an individual capacity of 70 MW. Together, these two units provide the dam's total installed hydroelectric capacity of 140 MW.

What are the physical dimensions and reservoir capacity of the dam?

The Shiyazi Dam is a concrete gravity dam with a height of 134.5 meters (441 feet). It withholds a reservoir with a total capacity of 321,500,000 cubic meters (260,644 acre-feet). The construction involved the use of both normal concrete and roller-compacted concrete.

Why was the construction of Shiyazi Dam considered difficult?

The construction process faced significant challenges due to the dam's location in a steep portion of Meilin Canyon. This topographical feature complicated the building process, requiring careful engineering to manage the concrete gravity structure within the canyon's constraints. The use of roller-compacted concrete alongside normal concrete was part of the construction methodology employed to address these site-specific challenges.

See also