by Abstract: at this stage, with the support of national policies, the assembly industry has developed rapidly, and a number of prefabricated residential projects with high prefabrication rate have emerged.
In such projects, the hoisting speed of prefabricated components has become the main factor limiting the progress of the construction period.
Combined with the project example, the actual hoisting time and influencing factors of prefabricated components in each process are observed and compared with the No.
1 residential building of Xishan Wutong project.
The main factors influencing the hoisting speed of prefabricated components and the improvement measures are summarized, which shortens the hoisting time of prefabricated components in prefabricated buildings and saves the construction period and cost while ensuring the construction quality.
1 research background: the whole process of Xishan Wutong project in Yongding town, Mentougou District, Beijing city is constructed by prefabricated components, in which the main body is constructed by prefabricated prefabricated main structure and the secondary structure is constructed by prefabricated light partition board.
The assembly rate of the main structure of the three 21 storey residential buildings in this project can reach 43%, including prefabricated composite boards, stair boards, air-conditioning boards, prefabricated exterior walls, PCF boards, prefabricated interior walls, staircase partitions and other prefabricated PC components; The prefabricated exterior wall adopts sandwich thermal insulation exterior wall (with large dead weight and easy damage).
Due to the tight construction period, the high prefabrication rate and wide variety of prefabricated components in this project take too long in the hoisting process of prefabricated components, resulting in slow construction progress.
The project monitors the production, maintenance, transportation, installation and other construction links of prefabricated components, and reasonably arranges the hoisting sequence of prefabricated components through BIM building information model technology to improve the hoisting efficiency of prefabricated components, Ensure the construction progress of the project and create benefits and efficiency for the project.
2.
Analysis of factors affecting the hoisting speed of prefabricated components Through observation and statistics on the hoisting of prefabricated components in Building 1 of the project, the influencing factors mainly include: 1) Lack of construction experience of labor service personnel.
As prefabricated buildings are emerging industries, and most of the construction site workers are migrant workers, they lack experience in the construction of prefabricated components.
2) The production quality of prefabricated components is not high, and the lifting holes are often blocked by mortar; The bolts in the lifting hole can not be smoothly tightened due to the rust caused by the maintenance of prefabricated components before delivery, and the lifting can only be carried out after manual cleaning.
3) The hoisting task of tower crane is complicated, because this project is a flow section operation.
Building 1 is divided into two construction sections.
When hoisting prefabricated components in one construction section, the other construction section needs to carry out hoisting operations of other construction materials and unloading, transportation and hoisting operations of newly mobilized prefabricated components.
4) For the impact of vulnerable prefabricated components, sandwich insulation prefabricated external walls and PCF plates are used in this project.
During the hoisting process, the rotation inertia of the components needs to be strictly controlled, because such components will be damaged in case of slight collision, which will cause potential quality problems for future engineering construction.
5) The hoisting sequence of prefabricated components is unreasonable.
There is no plan to hoist prefabricated components.
The components shall be hoisted to the working face before proceeding.
