The Maple Garden is the first recreational park below ground level in Taiwan. The vegetation planted throughout the garden increased Taichung City’s green coverage by 28,000 square meters, and contributed to lowering the urban heat island effect. Photo: ACE Geosynthetics Inc.

In Taichung City, Taiwan, city dwellers wandering through Maple Garden Park are actually meandering below ground level. In November 2012, landscape engineers working with geosynthetic products from ACE Geosynthetics Inc., Taichung, Taiwan, converted a 30,000-square-meter excavation site into an urban park oasis.

The area had originally been planned as the site of the Taichung International Expo Center, which was eventually built at another location. The planned center left behind a large, excavated opening about 20 meters deep. When city planners sought to turn the site into a park, they knew they had to work within a short time frame and on a limited budget. And they envisioned a park that made very limited use of concrete.

Engineers created the park by stretching geosynthetic canvas over the opening and into the site. The surrounding wall and slope of the opening were wrapped and reinforced with ACEGrid®, a geogrid woven by high-strength polymer yarns; geotextile ACETex®; soil bags; and vegetation mats.These formed the mechanically stabilized earth wall and slope. They also incorporated geomat containment mats and gabions into the landscape to help vegetation grow and to control erosion. A 200,000-cubic-meter ecological detention pond connects to the city drainage system to regulate floodwaters.

Taking a geosynthetic approach reduced the use of concrete and cut construction time and costs, giving residents quick access to a soothing, green oasis amid Taiwan’s bustling streets. Further enhancing the atmosphere, a restaurant was built in front of the pond, merging with the reinforced wall; an exhibition center was built at the Taiwan Boulevard entrance, and crushed aggregate, timber and wood chips were used in permeable pavements beside the pond.