ACEGrid® Reinforced Earth Structure with Galvanized Welded Wire Mesh Facing for Service Road of Second Baoshan Reservoir

To meet the water demand of Hsinchu Science Park, the government built the Second Baoshan Reservoir resulting in the relocation of the No. 45 highway in the reservoir area.

The original design was to rearrange the entire highway along the mountain ridge, which thus needs three additional bridges. Because the bridge construction equipment was difficult to get in and out of the site, the designer revised the original design for route and elevations.

The design of the No. 1 bridge was replaced by a height of 25 m ACEGrid^® reinforced earth retaining wall with a WWM facing. The second and the third bridge were also revised to be an ACEGrid^® reinforced embankment with a WWM facing with a height of 14 m. For the embankment, only two tiers were built because of the limitation of the property line. The width of the offset for each stage was only 1.5 m, and the structure's average slope was 3:1 (V: H). Permeable HDPE ACEPipe^TM and gravel were arranged at the bottom of each stage, and they were separated with the above-backfill by a non-woven geotextile layer. The inside of welded wire mesh facing was covered with an erosion control blanket to prevent surface soil from being washed away and also was beneficial for hydroseeding and landscaping.

1. Structure Safety
Traffic volume has been frequent because the site is close to the tourist zone of the reservoir. However, no visible settlement has been observed on the structural surface. The present structural conditions the cases are sufficient to verify the advantages mentioned above of the ACEGrid^® reinforced earth retaining structures with a welded wire mesh facing.
2. Landscape and Ecology
After hydroseeding, the wall can be quickly greened naturally and integrated into the local natural landscape. Where the site has no human intervention, the flourishing trees are close to the wild forest. Therefore, the construction of the ACEGrid^® reinforced structure has entirely avoided the incongruity of traditional reinforced concrete structures.