Need. According to the "People's Republic of China (PRC) Construction Law", "Regulations on Safety Production Management of Construction Projects" and other laws and regulations, before the project starts, the construction unit must set up a enclosure according to the regulations, and the pay-off construction can only be carried out after it is accepted by the construction administrative department. The setting standard of physical enclosure is not less than 1.8m for ordinary road sections, not less than 2.5m for urban main road sections, and white plastering for wall caps and external walls. Fence refers to the measures taken to isolate the construction site from the external environment and make the construction site a relatively closed space, including fences built with various masonry materials and maintenance bodies made of various molding plates.