Job Instruction for Installation of 1st Tier Reinforced Concrete Columns.

Contents

Introduction

Source Data

Space planning solutions

Specification of prefabricated building elements

Composition and scope of installation works

Mounting devices

Crane selection

Determination of the number of vehicles

Organization and Technology of Works

Labor protection during installation works

Safety precautions for erection of structures

Hourly installation schedule

Literature

Introduction

In our country, capital construction is one of the leading sectors of the national economy.

The technology of construction production is the science of methods of performing construction processes that ensure the treatment of building materials, semi-finished products and structures with a qualitative change in their condition, physical and mechanical properties, geometric dimensions, etc., in order to obtain products of a given quality. At the same time, the concept of "method" includes the principles of performing construction processes based on various methods of influencing the subject of labor using labor tools (construction machines, small mechanization tools, installation tools, manual and mechanical tools).

One of the main highly mechanized processes is the installation of prefabricated railway structures. It is based on the integrated use of installation, rigging and vehicles and largely depends on economic requirements when choosing mechanisms and cranes, which entails the prospects for the development of not only these means of mechanization, but also volumetric planning design solutions for the erected facilities.

The organization of construction production determines the essence and scientific basis of construction surveys and the design of the relationship between the implementation of construction processes in time and space, the logistics of construction, operational planning and production management.

Source Data Variant 008

Multi-storey building: M-6-4-3

Span width - 6m

Span length - 60 m

Height of the first floor - 6 m

Height of the middle floors - 6 m

Private upper floor - 6 m

Number of spans - 4

Number of floors -3

Column spacing - 6 m

Upper floor - large-span

Space planning solutions

The project was developed for the construction of a multi-storey building, which has a simple rectangular shape, a reinforced concrete frame .

Multi-story building - three-story, crane-free, floor height 6 m; building dimensions in plan view 24x60 m, column grid 6x6 m.

Installation methods of prefabricated reinforced concrete buildings

Installation methods are the determining factors of the technology of installation works, for the implementation of which work execution projects, process charts and process diagrams of installation of individual structural elements are developed.

Depending on the method of installation in the design position, we choose a semi-forced method of installation of structures using RSHI and a limited-free method using conductors for individual columns. We deliver elements for the building to acquired warehouses.

For a multi-storey building, we use a complex method of tiering, in which columns are installed, then girders and floor slabs together, forming a rigid spatial system. According to the delivery and storage conditions, we use installation from the warehouse.

The number and size of the grips are determined after determining the method of installation of the building and the direction of the installation process .

Crane selection

The machine set for installation works consists of a master machine (installation crane), auxiliary machines and equipment (loading and unloading machines and transport machines, load-grabbing devices, conductors, welding equipment, etc.).

Selection and calculation of machine kits for installation works shall be performed in the following sequence:

Technically acceptable mechanization options are established and possible types of cranes, auxiliary machines and equipment are selected;

If there are several machine sets that are technically acceptable for use in the installation of this building, the best is chosen by comparing technological and technical and economic indicators.

The selection of the lead mechanism of the installation kit - the installation crane - depends on the structural diagram and dimensions of the building, the mass and location of the mounted elements, the terrain of the site and other factors that make up the installation characteristic of the object.

Buildings of more than 2 floors are mounted by tower cranes.

When selecting an installation crane, it is necessary to take into account the compliance of its para-meters with the installation characteristics of the object under construction. Parameters are technical data characterizing cranes. The main operating parameters of the cranes are:

1) load capacity Q, t is the mass of the largest load that can be lifted by the crane to the highest and most distant point of the building while maintaining the stability and strength of its structures

2) height of NKR hook lifting, m - distance from parking level to hook with minimum height of cargo polyspast and specific departure (boom) of hook

3) distance of crane boom lstr, m - distance between vertical axis of crane turning platform rotation and vertical axis passing through centre of cargo hook holder

4) length of boom of crane Lstr, m - distance between center of axis of boom heel and axis of frame of load polyspast.

Having determined the necessary parameters, we select technically acceptable cranes according to technical characteristics. We choose the most effective crane and a set of machines by sequentially comparing the technical and economic displays-bodies.

Organization and Technology of Works

Warehouse organization.

When performing installation works using mobile tower cranes, prefabricated structures are located in stacks in an object warehouse in the crane boom area.

Stacks of prefabricated structures are located on one side of the building along the paths of the tower crane, which allows the crane operator to monitor the progress of slinging and lifting of installation elements.

Storage of structures, individual parts and installation elements from prefabricated reinforced concrete is carried out on a pre-prepared site. The storage site has a compacted earth base, planned with a slope of 1-20 for atmospheric water runoff.

Reinforced concrete prefabricated structures are located in a warehouse in stacks of several pieces in height or several pieces in one row in a position close to the design one. The exception is columns that are laid horizontally. Girders are laid in a stack up to 2 m high, but not more than 3 rows with linings located at a distance of 120 cm from the ends of the girders. The girders of the upper row of the stack must be braced with each other by twists behind the mounting loops.

Wall panels of buildings are arranged in stacks vertically in cassettes or in inclined position in pyramids.

The stored elements are supported by wooden linings and gaskets. Intermediate gaskets are not permitted. Thickness of liners and gaskets is not less than 25 mm and not less than height of slinging loops or other protruding parts of prefabricated structures.

Passages between stacks are arranged through every 2 stacks in longitudinal direction and 25 m in transverse direction. The width of the passage is 1m, and the gaps between adjacent stacks are 0.2m.

General requirements

Works on erection of buildings and structures should be carried out according to the approved work execution project (PDP), in which, along with the general requirements of SNiP 3.01.0185, the following are provided: structure installation sequence; measures ensuring required accuracy of installation; spatial immutability of structures during their pre-assembly and installation in the design position; stability of structures and parts of the building (structure) during erection; degree of structure consolidation and safe working conditions.

Combined erection of structures and equipment is performed according to WTP, which contains the procedure for work alignment, interconnected diagrams of installation levels and areas, schedules of lifting of structures and equipment.

Data on construction and installation works should be entered daily in the logs of works on installation of building structures, welding works, corrosion protection of welded joints, grouting of installation joints and assemblies, as well as their position on geodetic as-built diagrams should be recorded during installation of structures.

Structures, products and materials used in the erection of reinforced concrete, steel structures shall meet the requirements of the relevant standards, technical specifications and working drawings.

Transportation and temporary storage of structures (products) in the installation area should be carried out in accordance with the requirements of state standards for these structures (products), and for non-standardized structures (products) comply with the requirements of:

structures shall be in a position corresponding to the design one (girders, slabs, wall panels, etc.), and if this condition cannot be met, in a position convenient for transportation and transfer to installation (columns, stairways, etc.), provided that their strength is ensured;

structures shall be supported by inventory linings and rectangular gaskets located in the locations specified in the design; gaskets thickness shall be not less than 30 mm and not less than 20 mm higher than height of slinging loops and other projecting parts of structures; during multi-level loading and storage of the same type of structures, the liners and gaskets shall be located on the same vertical along the line of lifting devices (loops, holes) or in other places specified in the working drawings;

The structures shall be securely fixed to prevent overturning, longitudinal and transverse displacement, mutual impacts on each other or on the structure of vehicles; The fasteners shall be capable of unloading each element from the vehicles without disturbing the stability of the others;

Reinforcement outlets and protruding parts shall be protected from damage; factory marking shall be accessible for inspection;

Small parts for mounting connections should be attached to dispatch elements or shipped at the same time as structures in packagings with tags indicating part grades and their number; these parts should be stored under the canopy;

fasteners should be stored in a closed room, sorted by types and grades, bolts and nuts - by strength classes and diameters, and high-strength bolts, nuts and washers - by lot.

Structures during warehousing should be sorted by grades and laid taking into account the order of installation .

It is forbidden to move any structures with fiber.

Before lifting each mounting element, check:

compliance with its design mark;

condition of embedded articles and installation hairlines, absence of dirt, snow, ice, damages of finishing, priming and painting;

availability of necessary connecting parts and auxiliary materials at the workplace;

correctness and reliability of load-gripping devices attachment;

and equipped with scooping facilities, stairs and railings.

The installed elements shall be slung in the places specified in the working drawings and their lifting and supply to the installation site in the position near the design one. If it is necessary to change the slinging places, they must be agreed with the organization - the developer of working drawings.

It is prohibited to sling structures in arbitrary places, as well as for reinforcement releases.

Slinging diagrams of enlarged flat and spatial blocks shall ensure their strength, stability and invariability of geometric dimensions and shapes during lifting.

The mounted elements should be lifted smoothly, without jerks, swinging and rotation, using braces. When lifting vertically arranged structures, one brace is used, horizontal elements and blocks - at least two.

During installation of mounting elements, the following shall be provided :

stability and stability of their position at all stages of installation; safety of works;

accuracy of their position by means of permanent geodetic control;

strength of mounting joints.

Structures should be installed in the design position according to the accepted guidelines (risks, pins, stops, faces, etc.).

Structures having special embedded or other fixing devices shall be installed on these devices.

Mounting elements to be installed before disassembly must be securely attached.

Production quality control of construction and installation works shall be carried out in accordance with SNiP 3.01.0185.

The following documentation shall be provided during acceptance inspection:

as-built drawings with deviations (if any) approved by the manufacturer of structures, as well as installation organization, agreed with the design organizations - developers of drawings, and documents on their approval;

factory technical certificates for steel and reinforced concrete structures;

documents (certificates, passports) certifying the quality of materials used in construction and installation works;

acts of examination of hidden works;

certificates of intermediate acceptance of critical structures ;

as-built geodetic diagrams of structures position;

work logs;

documents on quality control of welded joints;

acts of structural testing.

Installation of prefabricated reinforced concrete structures. General Instructions

The acquired warehouse is located in the area of the installation crane.

Installation of structures of each overlying floor (tier) of a multi-storey building should be carried out after design fixation of all mounting elements and achievement of concrete (mortar) of ground joints of load-bearing structures of strength.

In cases where the strength and stability of structures during assembly are provided by welding of mounting joints, it is allowed to mount the structures of several floors (tiers) of buildings without grouting joints .

The use of a solution, the setting process of which has already begun, as well as the restoration of its plasticity by adding water, is not allowed.

Limit deviations from alignment of landmarks during installation of prefabricated elements, as well as deviations of completed installation structures from design position shall not exceed permissible values.

Installation of columns.

Installation of the columns of the underground part of the building in the foundation cups is carried out with the power of single conductors.

Columns of the first floor are installed in shells of foundations in such sequence. According to geodetic inspection of performed works, hairlines of columns axes are applied to upper faces of foundations. Axial hairlines are also indicated on columns prepared for installation. The bottom of the foundation shell is poured with concrete (if necessary) to the design elevation. Column is stroked, raised and installed, combining hairlines applied on it with axial hairlines on weight. on foundations. Column is adjusted and temporarily fixed by means of conductor. The column is disbanded and after installation of the row of columns in the same sequence, their position is finally checked, the columns are ground in cups with a concrete mixture.

The installation of the columns on the underlying columns is carried out using single conductors and leads a link of four installers in such a sequence. First, a conductor is fixed on the tip of the underlying column. The column fed to the installation site at a height of 30... 40 cm above the conductor is taken by installers and unfolded to the desired position. The installed column is temporarily fixed with adjusting screws. Change of column vertical position is provided by rotation of adjusting screws of upper race. The columns are disassembled only after it is attached and reconciled.

Deviations from the design position of the columns installed on the foundations or the underlying elements shall not exceed the following values (mm): displacement of the axes of the columns in the lower section relative to the layout axes or approximate sketches - 5; deviation of axes of columns of buildings and structures in upper section relative to layout axes at column height up to 8 m - 20, over 8 to 16 m - 25, over 16 to 25 m - 32, over 25 - 40.

Column verticality is checked by two theodolites set to two mutually perpendicular axes. Plumbs can be used only for reconciliation of single-storey columns of the upper floor with the grid of columns 6x6 and 6x9 m. After vertical alignment of the column, it is released from slings and reinforcement outlets are welded.

Outlets of joints are connected by semi-automatic bath by welding. To reduce the effect of welding stresses on the strength of reinforced concrete structures, reinforcement outlets are welded simultaneously on both sides diagonally.

Installation of girders, beams, trusses, slabs and coverings

The elements should be laid in the direction of the overlapped span in compliance with the design dimensions of the depth of their support on the supporting structures or gaps between the mating elements.

Installation of elements in the transverse direction of the covered span should be performed:

girders and inter-column (connecting) plates - combining hairlines of longitudinal axes of installed elements with hairlines of axes of columns on supports;

Girders, intercolone (binding) plates, are laid dry on support surfaces of bearing structures.

Slabs shall be laid on a solution layer not exceeding 20 mm in thickness, aligning surfaces of adjacent slabs along the seam on the ceiling side.

The use of linings not provided for by the design for leveling the position of laid elements by elevations without coordination with the design organization is not allowed.