Heading project Boom Tower crane Q = 8ton

Contents

Task setting and initial data

Summary

Calculation of boom steel structure

To Select a Beam Cross Section

Definition of overall dimensions

Load capacity calculation

Calculation of forces in steel structure rods

Checking Cross Sections of Features

Upper belt

Raskosa

Lower belt

Calculation of additional loads

Inertial load

Wind load

Horizontal grille

Bracing system

Check against maximum deflection condition

Calculation of bolted connection

Slice Calculation

Crumbling Calculation

Weld Joint Calculation

List of literature

Task setting and initial data

In this course design, the tower crane with the following initial data is considered:

Maximum lifting capacity Q = 8t;

Maximum departure L = 40m;

The width of the tower a = 2m;

Head height h = 8m;

Trolley weight m = 0.75t.

The purpose of the project is the practical mastery of the course "Construction mechanics and metal structures," obtaining skills in designing metal structures, performing load-bearing calculations using existing regulatory documents.

Summary

The main purpose of the tower crane is to serve the territory of construction sites of buildings and structures, warehouses, landfills, loading and unloading of materials from transport - during construction, installation and loading and unloading operations.

The boom of the tower crane is a metal structure that allows the cargo to be moved from one extreme position to another. There are lifting, beam and articulated booms of the tower crane. In this variant of task crane with beam boom is considered.

Beam arrows are single-weight and multi-weight. Multi-suspension booms are slightly lighter than single-suspension booms, but careful adjustment of the tension of the branches of the statically indeterminable suspension is needed; they are expedient when departing more than 50 m, so they are used less often.

The distinctive features of this design calculation are the multiplicity of solution options and the insufficiency of the initial data necessary for the calculation, i.e. the exact weight of the structure and dynamic loads are uncertain, since they also depend on the dimensions of the cross sections of the structural members. Therefore, the calculation has to be carried out using successive approximations, determining as a result the most optimal dimensions of the cross sections.

Calculation of boom steel structure

To Select a Beam Cross Section

Characteristic types of beam boom sections are given by

For beam booms, a single-lift trihedral shape with two lower driving belts is most expedient (the second diagram in Fig.2). With this shape, the bending moment in the driving belts will be relatively small [2]. The profile of the upper beam is a steel seamless hot-rolled pipe according to GOST 873278. For lower belts, rectangular sections obtained from two unequal angles according to GOST 851086 are optimal. Rails can be located on them, along which the carriage of the lifting mechanism moves. In some cases, rails are not used. Grid consists of steel hot-rolled seamless pipes.

Definition of overall dimensions

The length of one panel is assumed to be l = 4 m, so the number of panels on the entire boom length will be 10. The width of the boom is taken equal to the width of the tower: a = 2m. Boom height is taken equal to 1.5a = 3m.