ACE Geosynthetics Inc. Taichung City,

Project Details

Fabric 1

Producer: ACE Geosynthetics Inc.
Supplier: ACE Geosynthetics Inc.

Fabric 2

Producer: ACE Geosynthetics Inc.
Supplier: ACE Geosynthetics Inc.

Fabric 3

Producer: ACE Geosynthetics Inc.
Supplier: ACE Geosynthetics Inc.

Fabric 4

Producer: ACE Geosynthetics Inc.
Supplier: ACE Geosynthetics Inc.

Please describe the project specifications

This project is located in Central Taiwan, at the downstream of the flood plain of Zhuoshui river. The high flow period is from May to October, therefore its defense flood levels are up to 24,000 m3/s. The annual rainfall in the mountain catchment area reaches 2,000 to 3,000 mm. Therefore, this phenomenon is prone to erosion resulting in the loss of the highland beach.

This project requires mainly the use of ACETube® (geotextile tube) to carry out the protection of the flood plain slope and provide sheltering measures at the bottom of the spur dam. Moreover, it’s planned to carry out the laying of ACEFormer (geotextile mattress) to strengthen the surface of the slope and to enhance the ability for local river bank protection, disaster prevention and mitigation effects.

What was the purpose of this project? What did the client request?

The location of the repair works is located in the dam section of the river bank, it’s location from the outlet of Zhuoshui River is only about 5km, therefore the flood plain of river bank mainly comprises of river sediment, which is hard for the flood plain to resist river erosion effect, that causes the shrinkage of flood plain, seriously threatening the stability of river dyke and local resident’s life, property and safety.

The spur dam was used as river bank protection. Due to long-term foundation erosion of spur head, this caused loss of soil and its local settlement, also causing the gabion structure to be destroyed, making the pier head an exposed phenomenon. Therefore, it’s required to perform immediate repair to ensure the safety of the spur dam.

What is unique or complex about the project?

Since the local site weren’t any gravels found and mostly based of silts. So, it was decided to use local materials to fill in the ACETube®, to help achieve carbon reduction and to reduce the impact of the project towards the ecological environment of the river.

Spur dam was mainly installed with PC hollow pile and PC hollow cross beam. Firstly, a layer of PP geotextile was paved on the bottom of both sides of the dam side to slow down the problem of base subsidence. Secondly, depending on every spur dam’s exposed situation of each area, respectively ACETube® was filled with of 0.75m and 1.4m filled height, or also can be stacked together to stabilize the foundation of the pile head and achieve the reinforcement effect. ACETube® can prevent the partial scouring to occur and to increase the security and anti-erosion effects for the group of pier heads, increase the slow flow area, and improve the effectiveness of siltation. Also, in the most intense erosion areas, some gabions will be placed on top of ACETube® while filling the gaps in between with local sand and enhance the overall resistance to erosion.

On the slope of flood plain, according to the job site condition, we respectively place two layers of ACETube® with 25m or 50m of length and 1.5m filled height. Upon the layers of ACETube®, ACEFormer was placed on top and filled with cement mortar, thus it’s not only can protect geotextile tube’s structure, but also increase whole the slope strength.

What were the results of the project?

From 2011 until now, this project was carried out more than 1,100m in length for the protection of flood plain slopes and many sets of spur dam along this river. The method of using gabions and placing them on top of geotextile tubes instead of solely using gabions can save around 30~40% cost. It doesn’t only greatly reduce approx. 88% carbon emission, but also emphasize the benefit of geosynthetics for the green engineering. After the remediation, the shoreline is extended and direct erosion to the flood plain is reduced, improving successfully the safety of riverbank and embankment.

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