Open Cylindrical Caisson Construction Method For Water-saturated Sand, Gravel And Pebble Layer And Its Application

Caisson sinking construction nearby rivers, the lakes and beach, the surrounding waterenvironment always leads to saturated water conditions, associate with the geological conditionsconsisting of gravels and coarses, construction with conventional methods and equipments is verydifficult to achieve. The innovation and improvement of its sinking process is required to explore thenew construction technology for the conditions and related quality, safety, environmental protectionand other control measures. In this paper, based on Shanhaiguan sewage treatment plant project inQinhuangdao project, a detailed analysis and research about the pump house caisson constructionengineering, which is under the water saturated conditions, is present.Based on the actual situation of open caisson characteristics and engineering and the previousengineering experience, the safety and stability of Caisson in construction is analyzed and a reasonablesinking process and the quality controlling method are developed. Innovative construction is developedby using steel as a transverse back edge templates, and improved the formwork system, optimized theconstruction details. And the main facts influencing quality control of the production process of theopen caisson is analyzed.In order to make the caisson sinking construction meet the schedule requirements, it is optimizedto do routine method and equipment operation method in construction. The formulation of the sinkingconstruction technology and quality control program are designed, and the dynamic managementscheme on the construction process is proposed. We performed the construction process quality, safetyand environmental protection control and benefit analysis, and achiecved the schedule and qualityrequirements.With machinery, associate with manual coordination center island excavation method, not usingthe conventional equipment of undrained sinking construction method, instead to use sand digging shipand hydraulic grab for construction. After the test of practice, for the similar engineering environment,open caisson sinking in excavation, drainage subsidence and subsidence of the close combination ofconstruction methods and technical measures can save time and control well the construction quality.