Prestressed prestressed steel support system is composed of fish belly beam (composed of high strength and low relaxation steel strand as winding component, H-shaped steel as stress beam, and H-shaped steel support beam of different lengths, etc.), counterbrace, Angle brace, pressure beam, tie rod, triangle bond, pressure device, column and other components of the stress system.
Details >Original soil filling pile construction method1The excavation of the pipe jacking pit shall be carried out according to the construction scheme and specific environment. The length and width of the pit depend on the soil, the diameter and length of the top pipe section, the mechanical equipment, the pipe down and the method of excavation. In addition to installing the back of mechanical equipment for pipe jacking, guide rail and pipe jacking section, the working pit is also conducive to excavation and operation of staff outside the pit.
Details >Construction technology introduction of undisturbed earth taking and filling pile with full retaining cylinder1The undamaged soil taking and filling pile with full retaining cylinder is drilled and cut into soil by double power drill with built-in spiral blades in full retaining cylinder to form pile diameter;2Take out the soil in the protective tube without the original condition;
Details >The construction of intact earth taking and filling pile with full protective cylinder includes the steps of construction preparation, positioning and laying out, drilling, pumping concrete, inserting reinforcement and pulling out protective cylinder.
Details >According to the requirements of engineering design, if the H-shaped steel of SMW retaining pile must be pulled out and recovered after the structural strength reaches the design requirements, the H-shaped steel must be brushed with anti-friction agent before use to facilitate pulling out, and the surface of the steel is required to be evenly brushed with anti-friction agent.
Details >The construction method of double-wheel milling soil-cement mixing wall (CSM) is an innovative deep mixing construction method, which is a new technology of geotechnical engineering construction combining the existing hydraulic milling machine and deep mixing technology. That is, the original soil is cut by two milling wheels rotating around the horizontal axis, and the cement slurry is injected to form a uniform cement wall, which can be used as a cutoff wall, retaining wall or stratum reinforcement. Different from the traditional deep mixing method, the two groups of milling wheels rotate around the horizontal axis to form a rectangular reinforcement wall, instead of the single or multi-axis mixing head rotating around the vertical axis to form a cylindrical reinforcement wall.
Details >Foundation pit support is a measure to support, reinforce and protect the side wall of foundation pit and surrounding environment, so as to ensure the safety of underground structure construction and surrounding environment of foundation pit. The definition of foundation pit support in Technical Regulations for Building Foundation Pit Support in the industry standard of the People's Republic of China is as follows: In order to protect the construction of the underground main structure and the safety of the surrounding environment of the foundation pit, temporary retaining, reinforcement, protection and groundwater control measures are adopted for the foundation pit.
Details >1. Emergency plan for the horizontal displacement of the brace and Angle brace to the pit if it reaches or exceeds the alarm value: install jacks at the prestressing end of the brace and Angle brace, apply prestress in stages, and monitor the deformation until the deformation is stable.
Details >Concrete preparation requirements Pumped concrete shall meet the following requirements: 1. The supply station must provide Quality Certificate of Ready-mixed Concrete and concrete grading list; 2. 2, the initial setting time of concrete should not be less than 6 hours;
Details >1. Before construction, the site surface should be level off and all obstacles above and below ground must be removed; 2. Before starting the machine, it must be debuged to check the operation of pile machine and the smooth situation of feeding pipe; 3. Ensure perpendicularity: After the equipment is in place, it must be smooth to ensure that there is no inclination or movement in the construction process. Pay attention to ensure the vertical degree of the frame and the drill pipe, the deviation of the vertical degree shall not be more than 1%. During the construction, the hanging hammer is used to observe the perpendicularity of the two directions of the drill pipe and the horizontal water gauge is used to measure the leveling of the frame. If the deviation is too large, it will be adjusted in time.
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