Recently, although Vietnam has deployed many activities of anti- erosion and land-slide for the coast, no satisfactory result has been obtained. Therefore, the efficient application of assembled reinforced concrete components for protection of riverbanks, lakes and sea dykes of Ba Ria-Vung Tau Urban Sewerage and Development Ltd Company (BUSADCO) has been attracting the attention of national and international scientists. This technology has been voted and honored as one of top 10 science and technology events in 2015.

MANY OLD SOLUTIONS WERE UNSUCCESSFUL

According to the Ministry of Natural Resources and Environment, the situation of erosion and land slide on the coast of Vietnam has happened extremely complicated. According to incomplete statistics, all the coastal provinces have been eroded and landslided with the average of 15-30 meter/year... In the Middle of Vietnam, the beaches in Cua Dai, Hoi An, Phu Yen, Quang Tri have been seriously eroded and landslided. In Mekong Delta, the same situation has happened, especially in some places of Ca Mau, the land has been deeply eroded by the sea from 100-200 meters each year. Most of the area of U Minh forest near the sea of district have been swept away.

In Ba Ria-Vung Tau province, according to the statistics of the Department of Science and Technology, from Nghinh Phong cape (Vung Tau City) to Binh Chau commune (Xuyen Moc district) there are 6 places have been seriously eroded (Beaches of Thuy Van, Paradise, Cua Lap, Loc An, Ho Tram and Binh Chau). The Northeast wind with high waves hit the shore causing erosion with the length of 20km in total over 100 kilometers of the provincial coastline. The Department of Science and Technology gave out their warnings: " If there isn't any measures for anti-erosion and land slide, the coastline from Vung Tau City to Xuyen Moc will be destroyed. The internal civil works such as fishing ports, production facilities, houses, tourism projects along the coastline have been also in danger of "slipping" into the sea ".

Every year, thousands of billion dongs are invested in constructing works of anti-erosion in Vietnam. However, these works have mainly based on conventional solutions, are inclined to kinds of roofing embankment, embankment with welding tip with rubble-stone, building stone, simple concrete slabs or being more modern with the soft technology of Stabiplage …However, the cost for these anti-erosion solutions is quite high but they cannot ensure the effect of anti-erosion. Moreover, the construction of the above works in the tidal environment is often difficult to satisfy the requirements of technique and quality; many kinds of structure have been continuously broken...

The assembled reinforced concrete components for protection of riverbanks, lakes and sea dykes have been constructed to prevent the coastal erosion in Thai Binh province.

A BREAKTHROUGH FROM BUSADCO

In the context when the technology for anti-erosion of the coast cannot meet the requirements, the successful application of "assembled reinforced concrete components for protection of riverbanks, lakes and sea dykes" of BUSADCO in some provinces and cities instantly created a great reputation. The product was researched and manufactured by Dr. Hoang Duc Thao, General Director of BUSADCO and his colleagues. The product is produced as a component casted into hollow concrete block with thin walls, the structure is not used steel, using assembled adjoining with cubic structure in diverse shapes and variety of styles and sizes. This solution is open design, being easy for construction in slurry condition and the cost is reduced about 20-30% in comparison with conventional structures and other solutions.

In the mid 2015, BUSADCO applied the product for the project of embankment construction in Tien Hai – Thai Binh with the length of 4km. When being completed, the works was considered as being more sustainable than other sea embankment works by QUATEST 3 (Directorate for Standard, Metrology and Quality). The Chairman of Thai Binh people’s Committee, Mr. Nguyen Hong Dien said: “This works not only brings the effect of anti-erosion for the coastal area but also helps to encroach the sea about one kilometer.”

With the success of this works, BUSADCO continued to be approved for implementing the bending project with the length of 4.7km at the sea dyke in Thai Thuy district, Thai Binh Province. The project is expected to be implemented in 2016.

BUSADCO have been applied this new technology in the key projects in Ho Chi Minh city such as: the project of adjusting the irrigation system along the banks of Sai Gon river; The Project of upgrading and constructing Can Gio sea dyke ... Mr. Nguyen Ngoc Cong, Director of the Steering Center of Urban Flood Control Program (SCFC) in Ho Chi Minh said that: “assembled reinforced concrete components for protection of riverbanks, lakes and dykes" of BUSADCO is a breakthrough in anti-erosion innovation.

According to the evaluations of Mr. Hoang Van Thang, the Deputy Minister of Agriculture and Rural Development cum Director General of Water Resource Directorate and the scientists, BUSADCO product overcame almost weaknesses of conventional solutions for the embankment works for protection of riverbanks, lakes and sea dykes in our country. Specially, the preeminence of this solution is taking advantage of available sand at the beaches. In addition, the Investors and competent authorities can find it easy to check during the operation in order to detect the problems may occur to promptly repair such as subsidence, additional sand pumping into the embankment body if the sand is swept away.

Professor - Dr. Vu Dinh Phung, National University of Civil Engineering supposed that: The ability of anti-landslide, anti-erosion, anti- corrosion of BUSADCO solution is higher and it is more sustainable. With the thin and light features, it can be precast, easily assembled and has low cost that is suitable for the anti- erosion task in Vietnam.

Assembled reinforced concrete components for protection of riverbanks, lakes and the sea dykes using concrete material technology with thin wall, having size and technical features can be changed according to the conditions of topography, geology and using requirements. The body is main bearing part of structure, the sides and top surface were arranged the hole for wave breaking force in many different shapes. These holes are also for pressure breaking and air exhaust to ensure anti-overturn and anti-shift of structures in case of flooding. Under the body, there is a groove in order to hold the structures. The components are linked together by junctions such as rebated joints, bell- mouthed and barb joints... ------------------------------------------------------------------------------------------  BUSADCO product “Assembled reinforced concrete components for protection of riverbanks, lakes and the sea dykes" was allowed to establish the national standards by MOST; National office of Intellectual Property of Viet Nam issued the invention patent and utility solution; the Ministry of Construction issued the Certificate of appropriate technology and solution; Water Resource Directorate allowed to apply in the works protecting banks of river, lakes and dykes in the whole country. Based on the efficiency of product, the Water Resource Directorate has issued the Decision recognizing the product is technical progress and new technology. End of 2015, this technological solution has been recognized and honored as one of the top ten science and technology events in 2015. Council of Science and Technology (MOST) has already proposed the Ministry of Science and Technology to consider and introduce this technology to participate in climate change program period 2016-2020 in the national strategy on climate change.