Papers # 2012 Barcelona
As the key component of underground piping network for drainage, plastic inspection chambers have many major advantages and are also being applied more and more widely instead of traditional brick-built ones. Users become familiar with this new technique gradually. However there are two major problems which have negative influence on the popularization of plastic inspection chambers : connection with various pipes and anti-pressure performance to external loads. As plastic inspection chambers are pre-produced in factory, branch pipes are not able to connect with chamber body randomly like brick-built chamber. More over, due to that plastic pipes and plastic chambers are not popularized at the same time in China, varieties of plastic pipes are popular in market and their external diameters vary greatly from a large range. Therefore, it is difficult to connect chambers with pipes water tightly. Compared with traditional ones, users always feel that plastic chambers are light and have poor anti-pressure performance to external loads. It is necessary to design the structure and dimension of chambers under scientific study. The whole vertical load of chamber body is delivered to chamber base which is the key component. Inside vertical socket of connecting riser, 360°circle step is set to spread the vertical load equally and reinforcing ribs are made on base’s external surface to improving base’s vertical load performance. Also the reducer cone is a critical part of manhole. Through numerical computation and analysis, it is important to design vertical, radial and arch reinforcing ribs scientifically to improve anti-pressure performance. We know that cone can sustain vertical load of 90KN through test and the result closely match the theoretical analysis.