Valley Tailings Pond Geomembrane Liner Design

I. Project Background

Valley-type tailings ponds are widely used in modern mining because of their natural terrain advantages. Our project is located in a mountainous area where a central valley provides a natural foundation for storage.

The pond is designed to hold tens of millions of cubic meters of tailings. It operates safely for several decades and supports stable mine production. At the same time, it reduces environmental risks by containing tailings within a controlled system.

In addition, the location provides reliable geological support. This advantage lowers construction costs and improves long-term safety. As a result, the valley-type pond has become the preferred choice for many large-scale mines.

II. Construction Process

1. Dam Construction

Initial Dam:
The initial dam was built using a rolled earth-rock structure. Its foundation was placed directly on exposed bedrock. Before construction, the surface was cleaned. Workers removed humus, loose rocks, and debris until solid rock appeared. Anchoring and grouting reinforced the stability.

Most construction material came from nearby blasting areas. Stones were screened to meet strength and size standards. During filling, each layer was compacted with large rollers. In addition, the upstream and downstream slopes received filter layers. These layers prevented fine particles from washing away and ensured drainage.

Subsequent Dam Raising:
As tailings were discharged, the dam height increased. Engineers used the upstream method, placing tailings sand as fill material. Discharge points were adjusted to keep deposition uniform. Moreover, slope conditions were monitored closely. When issues appeared, the discharge plan was updated immediately to ensure safety.

2. Anti-Seepage System

HDPE Geomembrane:
A high-density polyethylene geomembrane served as the main anti-seepage barrier. It provides strong chemical resistance, UV stability, and long durability. Before installation, the reservoir bottom was leveled and cleared of sharp objects. This step prevented puncture and improved contact.

Workers welded the sheets using hot-melt equipment. Temperature and speed were tested before operation. Each weld was inspected with both air pressure and vacuum testing. As a result, the pass rate reached 100%.

Bentonite Blanket:
Beneath the geomembrane, a bentonite waterproof blanket added extra protection. When exposed to water, the bentonite swells and fills small gaps. Workers ensured proper lap width and fixed the blanket with anchor nails. This process created a complete sealing system.

3. Drainage System

The pond design included an internal drainage system. A gravel filter layer was placed at the dam foot, along with perforated plastic pipes. These pipes collected seepage water and discharged it outside. In addition, surface ditches guided rainfall away from the dam body.

This combined design reduced pore pressure inside the dam. It also prevented slope instability caused by water accumulation. In short, the drainage system guaranteed both safety and efficiency.

4. Flood Discharge Facilities

To handle extreme weather, engineers built a flood discharge channel and spillway. The spillway was lined with reinforced concrete to resist erosion. Moreover, its capacity matched the maximum flood level predicted for the region.

During operation, water levels were monitored daily. If heavy rainfall occurred, staff adjusted the discharge process immediately. This proactive system protected the dam body and extended its service life.

III. Construction Quality Control

Strict quality control was applied throughout construction. First, material testing confirmed that soils and rocks met design standards. Second, compaction tests ensured each dam layer achieved the required density.

In addition, supervisors inspected every welding seam of the geomembrane. If defects appeared, repairs were carried out on the spot. Continuous monitoring created a reliable anti-seepage structure.

Moreover, engineers documented every stage of the process. This record allowed later verification and provided technical guidance for future projects.

IV. Environmental Protection Measures

The project emphasized environmental responsibility. During construction, dust suppression and noise reduction measures were applied. In addition, wastewater from construction areas was collected and treated before discharge.

Vegetation was planted on the downstream slope of the dam. This measure reduced erosion and improved the local landscape. Furthermore, the project included a monitoring system for groundwater and surface water. Regular testing ensured that no pollution spread beyond the site.

As a result, the pond achieved both engineering safety and environmental sustainability.

V. Project Significance

This valley-type tailings pond demonstrates advanced design and construction practices. By integrating stable dam structures, efficient anti-seepage systems, and reliable drainage facilities, it provides long-term safety.

Moreover, it supports continuous mine production and reduces environmental risks. The combination of engineering strength and ecological protection makes this project a model for the mining industry.

In conclusion, the project proves that safe and sustainable tailings management is possible. It offers valuable experience for similar large-scale mining operations worldwide.