A Floating Offshore Barrier: Restoring the Ecosystem of Waisanding Sandbar
In recent years, the establishment of sediment-trapping dams and the petrochemical complex at Mailiao has led to a shortage of sand replenishment for Waisanding Sandbar. Scholars predict that without intervention, this “moving national territory” may become a disappearing one by 2028. As a natural offshore barrier, Waisanding protects Dongshi’s oyster farming industry, which supplies half of Taiwan’s fresh oysters, from coastal erosion and storm surges. Addressing this crisis is critical for both ecology and local livelihoods.
This project proposes a floating offshore barrier, utilizing tensegrity structures and bending-activated mechanics to create a lightweight structural system—a sustainable alternative to traditional offshore breakwaters, which rely on continuous concrete pouring. The goal is to establish a non-invasive, eco-friendly barrier that protects the seabed, restores marine ecosystems, and supports sandbar regeneration.
Design Strategy: A Two-Part Floating System
Positioned 70 meters offshore, where the water depth is only 2–2.5 meters, the structure is designed as a semi-hollow, lightweight composition. It employs floating shell units and sand-trapping mesh, anchored through a balanced system of tensile forces to facilitate sand accumulation and shoreline stabilization.
1. Floating Shell Tensegrity Structure
Above the water, a modular tensegrity shell system forms the core floating units of the offshore barrier. These prefabricated, scalable modules serve as wave breakers, reducing wave energy before it reaches the shoreline.
2. Dual-Layer Sand-Trapping Mesh
Below the water, a bending-activated tensegrity structure functions as a sand filtration system, facilitating sediment deposition while minimizing seabed disturbance.
Towards a Sustainable Future
By replacing heavy, gravity-based concrete block installations with a lightweight, modular system, this design aims to restore the sandbar’s ecological function, ensuring the survival of Waisanding’s coastal environment and oyster farming industry. Ultimately, this approach seeks to harmonize human industry with natural preservation, offering a resilient and adaptive coastal protection solution.
因應外傘頂洲近年因攔砂堰與六輕石化工廠的建立導致沙源補充不 足，學者研判，如不設法保固，預計在 2028 年「移動的國土」可能將 成為「消失的國土」。外傘頂洲潟海造就的東石養蚵產業，就佔了全國 鮮蚵的一半產量，外傘頂洲作為海上屏障，確保東石不受風浪侵襲， 是我們須正視的議題。
此設計透過拉張整體結構 (Tensegrity) 與撓曲試驗 (BendingActivated) 創造出輕質材料應用的結構體，進而取代由澆灌水泥一灌到底的「傳統式離岸堤」。藉此以不傷害海床，並歸還海底生態又能積沙養灘的「漂浮式離岸堤」為設計目標。
漂浮式離岸堤設置於沙洲外海 70 公尺處，其所在水深只有 2~2.5 公 尺。因此結構以半空心，輕質量的組構為前提，以漂浮薄殼單元與攔沙網的上下拉力平衡固定於海床上，以利養灘工程。
漂浮式離岸堤又細分成底下兩大部分 :
第一部分 : 漂浮單元拉張薄殼結構
海平面上以拉張整體結構做為離岸堤塊體的漂浮單元模組，進行量化與模組單元拼裝，也以此薄殼系統進行擋浪之功能。
第二部分 : 雙層攔砂過濾網
海平面下以彎曲激活張拉整體結構 (Bending-Activated Tensegrity) 做為底床積砂的攔沙網裝置進行固沙。
我們的最終目標希望透過以輕量結構且可被模組化的方式取代現有海岸工程重力式的水泥塊鋪設，並應用於外傘頂洲的外海進行沙洲 生態復育與人文產業保存，達到維護自然生態與人文產業的呼應與共構。
