Basis of Structural Design Calculation

Contents

Project Task

Introduction

1 Marking plan

2 Calculation of slab

2.1 Initial data

2.2 Determination of loads and forces

2.3 Calculation of strength of normal sections

2.4 Calculation of strength of inclined sections

2.5 Selection of mounting loop

3 Column calculation

3.1 Initial data

3.2 Determination of loads and forces

3.3 Calculation of column by bearing capacity

3.4 Calculation of the column for transportation forces and installation

3.5 Column Reinforcement

4 Calculation of central-loaded foundation

4.1 Initial data

4.2 Determining the size of the foundation foot

4.3 Determination of foundation height

4.4 Strength of foundation for pressing

4.5 Selection of reinforcement

List of sources used

Introduction

Reinforced concrete is a building material in which concrete and steel (reinforcement) are connected in monolithic whole.

The idea of ​ ​ creating reinforced concrete from two materials different in their mechanical characteristics is the real possibility of using concrete for compression work, and steel for tension .

The joint work of concrete and reinforcement in reinforced concrete structures was possible due to the profitable combination of the following properties:

1) adhesion (gluing) between concrete and reinforcement surface, which occurs during concrete mixture hardening;

2) close in value coefficients of linear expansion of concrete and steel at t ≤ 100˚C, which excludes the appearance of internal forces that can break the adhesion of concrete with reinforcement;

3) protection of reinforcement enclosed in concrete body against corrosion and direct impact of fire.

Today it is difficult to find such an area of ​ ​ the national economy in which reinforced concrete would not be used in construction.

Advantages of reinforced concrete: due to its high physical and mechanical properties, it provides significant resistance to static and dynamic loads, seismic and vibration-resistant, durable, fire-resistant and well resists atmospheric effects. Up to 7080% of the mass of reinforced concrete is made up of widespread materials (sand, gravel or crushed stone and water); the strength of concrete over time not only decreases, but can even increase; concrete can easily be given any suitable structural and architectural forms; maintenance costs for maintenance and maintenance of reinforced concrete structures are low.

The disadvantages of reinforced concrete include: a relatively large mass of structures; increased heat and sound conductivity; complexity of work, especially in winter; the need for qualified personnel, special equipment (when manufacturing prefabricated reinforced concrete structures in factory conditions); possibility of cracks before application of operational load due to shrinkage and creep of concrete, as well as for technological reasons.

Reinforced concrete is widely used in industrial, housing and rural construction, in hydraulic, mine and mining structures. Reinforced concrete is used in mechanical engineering for the manufacture of frames and supporting parts of heavy presses and machine tools, in shipbuilding .

Depending on the construction methods, reinforced concrete structures can be prefabricated, monolithic, prefabricated.

Precast reinforced concrete is the main building material in modern construction.

The essence of precast reinforced concrete lies in the fact that all elements of the structure are made at the plants of reinforced concrete products. On the construction site, a building or structure is assembled from finished structures.

The use of prefabricated reinforced concrete structures of factory manufacture allows to significantly reduce the consumption of steel, wood and labor costs for expensive formwork and scaffolding, but requires heavy transport and lifting mechanisms, careful execution of joints and junction assemblies of elements.

Cast-in-situ reinforced concrete structures are erected with preliminary arrangement of supporting scaffolding and formwork (forms), in which reinforcement is installed and concrete mixture is laid. Scaffolding and formwork can be removed only after the concrete has acquired sufficient strength.

Monolithic reinforced concrete structures are widely used in structures that are difficult to divide and unify, for example, in hydraulic structures, heavy foundations, bunkers, swimming pools, in structures erected in a mobile or sliding formwork (silos, chimneys, multi-storey tower buildings, etc.). When erecting monolithic structures under conditions of negative temperatures, concrete heating is necessary.

Prefabricated monolithic reinforced concrete structures are a combination of prefabricated elements and monolithic concrete laid at the construction site. Prefabricated monolithic structures in comparison with prefabricated ones differ in the simpler arrangement of joints.

According to the type of reinforcement, reinforced concrete with flexible reinforcement in the form of steel rods of a round or periodic profile and with load-bearing reinforcement are distinguished. The bearing reinforcement is shaped rolling steel - angled, channel, I-beam (called rigid reinforcement) and spatial welded frames made of round steel, which accept the load from the suspended formwork and freshly laid concrete mixture.

One of the drawbacks of reinforced concrete structures is crack resistance. To eliminate this lack of reinforced concrete, the so-called pre-stressed (prestressed) structures are used. The idea of ​ ​ these is to preliminary (before applying an external load) reduction of concrete in areas in which tensile stresses are possible after the application of the load, causing the formation or opening of cracks. In prestressed reinforced concrete structures, reinforcement is subjected to preliminary tension, and concrete is subjected to compression.

Reinforced concrete with flexible reinforcement is the most common in construction.

Reinforced concrete structures began to be used in construction in the second half of the 19th century in connection with the development of industry and transport .