Combined with the engineering practice of Shanghai Fengxian District Youth Activity Center Project,in view of the characteristics of continuous circular arch on the top of most single buildings and the large number and types of special-shaped steel components,a set of key hoisting construction technologies,such as high-precision measurement and control,optimization of connection nodes,secondary pre-assembly and controllable small deformation hoisting,are adopted.It solves many problems such as complex special-shaped steel structure component processing,on-site assembly,high-altitude hoisting in place,welding quality and so on,which can provide reference for similar special-shaped steel structure project construction.
Combined with the engineering practice,the corresponding technical research is carried out to solve the construction problems of long cantilever length,short construction period and narrow site of variable cross-section H-shaped steel reinforced concrete beam.On the premise of ensuring the construction safety and not affecting the construction of the lower concrete structure,the formwork erection and pouring of the SRC beam were completed by using the self-bearing hanging formwork,the high-altitude hanging operation platform and the high-altitude formwork erection platform through innovative methods.The practice shows that the construction technology of high-altitude platform composed of self-supporting hanging formwork,hanging operation platform and high-altitude formwork support platform has the advantages of safety,reliability,simple construction,saving construction period and reducing cost,which is worth popularizing and applying in engineering.
Combined with the engineering practice,the sinking precision control problem of open caisson construction in deep and thick silt layer is tackled.By designing the sinking construction process,a waterproof curtain and a sinking-aid stabilizing pile are used for auxiliary sinking.By adopting the pre-pasting ash cakes and adjusting the left and right inclination for removing or increasing the ash cakes in the sinking process,by adopting a mode of combining drainage sinking and non-drainage sinking for carrying out twice sinking and carrying out twice underwater bottom sealing,the safety and stability of the sinking of the open caisson in a deep and thick silt layer are ensured,the speed and accuracy of caisson sinking are guaranteed and can provide a reference for the construction of large caissons in deep silt layers in other cities.
Taking the construction of a supporting pedestrian tunnel for traffic relief in Guangzhou Baiyun International Airport as an example,the current environment and construction difficulties of the project are emphatically analyzed,and combined innovative technologies such as horizontal freezing reinforcement technology of pipe jacking receiving portal,rectangular pipe jacking shell abandonment construction technology without receiving conditions,curtain grouting reinforcement technology of rectangular pipe jacking tunnel,and key technology of ecological underground excavation construction are adopted.It solves the problem of rectangular pipe jacking construction safely reaching the designed receiving position and smoothly connecting with the original subway station under the sensitive environmental conditions of complex geology,complex pipelines and no receiving site.The construction technology has high safety,can effectively isolate groundwater,reduce the settlement and collapse of the tunnel entrance,and has little impact on the surrounding environment and pollution,which can provide a reference for similar projects.
Taking the Urbancore reconstruction project in Plot J as the background,as the surrounding buildings have been completed,the construction site is limited,and the upper steel staircase structure is complex,the construction period is urgent,and the construction is difficult.The installation and construction of complex steel stairs in existing buildings are implemented from the aspects of construction equipment selection,installation area division,temporary construction measures and safety measures.Through the application of the construction software,the construction measures are simplified,the construction period is shortened,and satisfactory results are achieved,which has reference significance for similar construction projects.
