Communication tower infrastructure type
The communication tower foundation safely and reliably transfers all the loads of the upper structure to the foundation and maintains the overall stability of the structure. It is an important part of the communication tower structure.
The foundation selection and foundation layout of the communication tower are closely related to the superstructure form, structural layout, external load type, construction site and geological conditions. Reasonable foundation selection and design are essential to reduce structural costs, shorten construction periods, and ensure structural safety and reliability.
In addition to the top-level tower erected on the roof of the communication tower, there are some space truss towers, single-tube towers, and cable towers that fall on the ground. Space truss towers are usually made of independent foundations and connected together by connecting beams (Figure 10-1) to jointly bear the horizontal load (wind load and earthquake action) on the tower, the structural self-weight, etc. Control the role.
Because the wind load is a random load, the magnitude and direction of the wind force are arbitrary and pulsating, and the force acting on the foundation is also arbitrary and pulsating.
The space truss steel structure used in the communication tower is relatively light, and the vertical load of the platform on which the communication antenna is suspended is not large, so the tension or pressure tower on the top surface of the foundation under the triangular or quadrilateral truss is alternating, and the tension value is usually as high as the pressure value More than 70%. The pull-out design of the truss tower is particularly important, and sometimes the pull-out design of the foundation plays a leading role.
Single-tube communication towers are mostly cylindrical (conical) structures. Most of the foundation is made of square or round plates
The diameter of the single-pipe communication tower is small, so the basic size is not large. Under the action of the bending moment, the edge of the foundation slab may be pulled away from the foundation. According to the "Code for Design of High-Rise Buildings" (GB 50135 approved for use), the bottom of the foundation is not allowed to be separated from the foundation soil under the standard combination of normal service limit state load. Therefore, it is necessary to expand the slab foundation to enhance the flexibility of the foundation floor. If the foundation is not good, use a slab foundation to add piles.
Pull line communication tower mountain mast scarf center foundation and fiber rope ground anchor foundation composed of two parts (Figure 10-3). The central foundation supports the shaft and bears the pressure and horizontal thrust of the shaft. The ground anchor foundation fixes the fiber rope and bears the tensile force of the fiber rope upwards along the diagonal.
