At present, there are three kinds of trenchless rehabilitation technology for underground drainage pipeline collapse in the world (including more than 10 kinds of process technologies). One is to use resin curing to form a new drainage pipe inside the pipe, such as CIPP, on-site curing and other processes. The other type is to use small pipes to pass through large pipes, and insert small drainage pipes inside the original pipes to solve urgent problems, such as short pipe lining, U-shaped pipe dragging and other processes. The last type is to use the spiral pipe method to form a new pipe inside the original pipe by winding method, such as spiral winding method.
The overall advantage of the trenchless rehabilitation is that the negative impact of the rehabilitation is small, the space occupied is relatively small, and the impact on the ground, traffic, environment and surrounding underground pipelines is very weak. Therefore, it is imperative to promote the application of trenchless rehabilitation technology in the field of drainage pipeline rehabilitation.
The difficulty of the promotion of trenchless rehabilitation technology lies in the high rehabilitation cost, which is prohibitive for many small and medium-sized cities. In fact, considering the traffic, the risk of surrounding pipeline excavation and the quality of life of citizens, the cost of trenchless rehabilitation is acceptable. And the main reason for the high cost is that the materials are completely imported. In the near future, this technology will be accepted by the drainage and municipal industries, and it will be widely used in the rehabilitation of urban pipelines.
As an important branch of trenchless technology, pipeline trenchless rehabilitation technology plays an important role in solving the problems of existing pipelines. At present, pipeline repair technology is still in its infancy in some countries and is still far from the mature stage. There are still many problems to be solved, in particular, relevant technical and management institutions should formulate some practical standards and specifications as soon as possible.
Pipeline rehabilitation technology has great advantages in terms of economic cost, social cost and environmental cost, and has a wide range of applications. We look forward to seeing a better development of pipeline trenchless rehabilitation technology in the near future.