Yuejin Port has become more beautiful! Stacked stone revetment returned to nature, challenged zero cement and won the "Golden Apple Award"

Published: 2024-05-18 Author: mysheen
Last Updated: 2024/05/18, Yuejin Port has become more beautiful! Stacked stone revetment returned to nature, challenged zero cement and won the "Golden Apple Award"

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When it comes to Yuejin Port, I think of the bright Lantern Festival, which has been held for ten years, attracting hundreds of thousands of people to visit every year. However, in the past, the stream of Yuejin Port was dirty and smelly, the revetment continued to collapse, the construction projects were not integrated for more than a decade, and the environmental problems had not been improved for a long time. In recent years, the engineering unit has adopted the ecological construction method, and has been successfully renovated, and has been selected as the second "Golden Apple" water environment project by the river citizen group "Taiwan River Network".

Two years ago, Wen Jianan, manager of Chongjun Engineering Consulting Company, took over the plan to improve Yuejin Port, including non-governmental ring groups into the consultant group, using artificial diamond-shaped stone arrangement instead of cement to renovate the water bank of Yuejin Port, and selected native tree species as street trees at the top of the dike to make Yuejin Port glow again.

Yuejin Port, which is adjacent to farmland and housing, has a popular Lantern Festival every year after waterfront renovation (Photo Source / Tainan Municipal Government), but the water quality is dirty and smelly. Yuejin Port is in urgent need of resurrection.

Yuejin Port is located in Yanshui Town, Tainan. In the past, Yanshui Town was close to the inland sea of inverted wind. The triangle formed by the Bachang River in the north and the Jieshui River in the south is just like the new moon, so the salt water is also known as "Yuejin" and "Yuegang". The town of Yanshui in the Ming and Qing dynasties was a necessary place for people and goods to travel between Zhuo and Fu City.Because of frequent trade and transshipment of people, the town of Yanshui was juxtaposed with Fu City, Lugang and Yuanling, and had the reputation of "one government, two deer, three cloisters, and April Jin".

Later, due to a large number of river sand and gravel deposits, the inland sea lost its transport advantage due to the blockage of the port, and finally gradually declined. Over the past decade, the Yuejin Port Lantern Festival has attracted hundreds of thousands of visitors every year. In order to restore the prosperity of Yanshui Town, the Tainan Municipal Government wants to improve Yuejin Port through the "National Water Environment improvement Plan" and the "Town Heart Plan."

Is the water environment problem in Yuejin Port very serious? Wen Jianan, manager of the Chongjun Engineering Consulting Company, who is in charge of the renovation plan, says that people who come to see the Lantern Festival will not stay long, while local residents think that Yuejin Port smells dirty, the waterside revetment is constantly collapsing, and water activities have no future. "the Lantern Festival can attract outsiders. If you want people to like Yuejin Port, you should start with improving the environment."

Yuejin Port Lantern Festival is the annual event of Tainan Salt Water (Photo Source / Tainan Municipal Government). In the past, water environment projects addressed the symptoms but not the root causes, and bank revetment instability often collapsed.

Walking along the river bank, Wen Jianan explained the ingenuity of each project detail. The first is the stone revetment. The purpose of the revetment on both sides of the river is to prevent the slope from collapsing and provide a buffer for users. In the past, the waterfront project of Yuejin Port usually changed the original waterfront structure, resulting in the loss of connection and instability between the water area and the revetment. "the previous engineering method had a low budget and did not get to the root of the problem."

Wen Jianan explained that Yuejin Port was seriously silted up. In the past, when the waterfront project started, as soon as the silt on both sides was dug up, the slope would collapse due to lack of stability. Then, in order to clear the silt again and build the revetment, the construction will adopt the "foot truncation type", meaning that after the foot of the slope is cut off, the revetment will be made of new building materials. "the material that is usually used is cement."

What's wrong with the construction like this? Wen Jianan said that this approach seems to save money, but the subsequent annual maintenance funding. On the other hand, the soil layer on both sides of the bank and the building materials of the revetment are different, "it is tantamount to a fault between the bank and the water area," causing the revetment to become unstable and collapse, and the trails and ramps of the bank will also collapse due to the loss of the bottom support of the revetment. "it has to be repaired all the time. Local governments do not necessarily have so much maintenance capacity." In addition, the trails built are often not moving well.

Before the regulation of Yuejin Port, the water quality was improved, dirty and smelly (provided by Wen Jianan) manual stone discharge was more stable, and the cross section was made to slow down the trailing of aquatic plants.

"if you want to meet the ecological needs, cement is obviously not a good choice." Wen Jianan said that the revetments of rivers and streams in nature have two major features, namely, a stable footing at the bottom and a gentle slope. The stable footing should be able to withstand the erosion of water, and the gentle slope can avoid the loss of soil and rock in the slope.

The water flow velocity of Yuejin Port is slow and the scouring condition is less. Wen Jianan takes artificial stacked stone as the footing. These stones, no matter their size or shape, are selected and stacked one by one. Actually stepping on the stacked stones on both sides of the water bank, there will be no shaking or instability.

Wen Jianan specifically stated that masonry is the skill of an ancient craftsman. Craftsmen will select stones according to their needs and stack them according to the shape of each stone, so that the stacked stones can bite and hold each other firmly, and their stability cannot be achieved by throwing machines and tools.

In addition, Wen Jianan is very particular about the height of the stack. "We have a special section." He explained that the bottom stacked stones do not coincide with the water surface, and the two layers of stones under and above the water surface are kept at a distance of 5 to 10 centimeters from the water surface, respectively. "the stone surface does not coincide with the water surface, but is like a ladder." This arrangement is to slow down the trailing speed of aquatic plants to facilitate follow-up maintenance and management.