Building erection technology - industrial building

Contents

CONTENTS

Introduction

1 Design Input

2 Counting the number of mounting elements

3 Installation equipment for reconciliation and temporary fixation of elements and 

his choice

4 Technology for making joints and joints, determination of their volumes

5 Production process of installation of prefabricated reinforced concrete structures

6 Determination of initial data for selection of installation crane

7 Determination of labour intensity and duration of installation works

8 Technical and economic evaluation of installation work options

9 Determination of the composition of brigades and units

10 Development of a one-storey planning plan 

industrial building

11 Development of safety measures during installation of precast reinforced concrete structures

List of literature

INTRODUCTION

In the creation of construction products, technologies for its production, both in general and in individual parts, play a large role. The technology determines in what order and in what way the construction process should proceed, which is a combination of three main elements of any production: labor resources, labor items (material resources), technical means (tools). Therefore, the technological regulations for construction work can be considered the "fourth element" of the construction process.

The technology of erecting buildings and structures combines simple and complex technological processes that differ in the main elements of production. Technology efficiency depends on the level of process interaction. The higher the level of their combination, the more efficient the technology.

During the course work, the procedure for designing the installation routing of a one-story industrial building was studied.

The course work is performed in accordance with the design assignment and the applicable codes and regulations.

Design Input

The work considers the technology of erecting a one-story industrial building from reinforced concrete elements. The construction of the building is carried out on the territory of Donbass. The building is a 3-span building with a pitch of extreme columns - 6.0 m, medium columns - 6.0 m. The length of one span is 18 m. The building frame is a collection of load-bearing structures: columns, trusses, paving plates, etc.

Count the number of mounting elements

Structural solutions of the building under construction

The scope of installation and related work depends on the methods and methods of installation. Based on the structural diagram shown in Figure 1, the number of installation elements (structures) or the scope of basic work is calculated

After the design of the variants and the decision to consolidate the installation elements, the calculation should be clarified.

A separate list is drawn up for items that are being pre-assembled on site.

The scope of work for structural reconciliation and fixation depends on the selection of installation equipment and methods for connecting the prefabricated elements to each other and is determined after the final selection of equipment.

It is recommended to include the necessary auxiliary and preparatory works, such as installation and rearrangement of conductors, lifting and rearrangement of scaffolding for installers, installation and rearrangement of bracing, etc.

Installation equipment for reconciliation and temporary fixation of elements and its selection

The most time-consuming and complex process is to reconcile and temporarily secure the columns. This complexity is due to the high weight and high height, as well as the instability of the columns during installation.

Various means are used to reconcile columns:

- wedge and jack devices (metal, reinforced concrete and wooden wedges; wedge inserts; jacks);

- conductors (struts with adjustable struts; frame jacks with horizontal jacks, etc.).

Temporary fixation of columns with a height of more than 12 m by conductors is not enough, and they are additionally fastened by bracing in the plane of the most flexible column.

Bracing, conductor, wedges and other fasteners are removed only after the columns are fixed in joints and concrete acquires at least 70% of design strength.

Screw spacers are used to reconcile and temporarily fix the trusses and beams of the coating, the number of which is determined by the work design. Usually for trusses with a span of 18 m, one spacer is used, and for spans of 24 and 30 m - two.

Workers climb to the mounting units by mounting stairs, attachments or hinged stairs. Stairs and platforms are fixed on columns by removable clamps or loops, which are welded to embedded parts of columns

Technology for making joints and joints, determining their volumes

The process of sealing joints (Table 3) of load-bearing prefabricated reinforced concrete structures consists of welding of reinforcement outlets or embedded parts, corrosion protection of embedded parts, grouting of joints with concrete or mortar. At sealing of joints of enclosing structures additionally heat, waterproofing and sealing are performed.

Scope of works for termination of joints of mounted structures shall be calculated taking into account material consumption during joint arrangement

Production process of installation of precast reinforced concrete structures

The installation complex of works is divided into preparatory, main and auxiliary processes.

Preparatory processes - checking the state of structures, control assembly, pre-assembly, reinforcement of structures, equipping of structures with devices for their temporary fixation and safety of work, application of installation hairlines on mounted elements, suspension of scaffolding and stairs performed before lifting of structures.

The main process is the installation of structures in the design position. It consists of slinging of mounting elements, lifting, aiming and installation of them on supports, alignment, temporary or installation fastening (electric welding, riveting, installation of permanent bolts, corrosion protection of welded joints, joints and joints with concrete or mortar), disassembly.

Auxiliary processes are the production and repair of various devices and technological equipment, the manufacture of certain parts, including individual small structures for buildings and structures being built, as well as the installation of anchors, the testing of load-gripping devices and cranes, the construction and disassembly of various networks in the installation area, the testing of mounted structures, etc.

One-story industrial buildings are built from unified standard sections consisting of the same type of structures, unified spans, column steps, etc.

Installation methods of building structures determine the sequence and progress of the entire technological process of building erection. The choice of the installation method depends on the space planning and structural solutions of the buildings, as well as on the specific construction conditions. Organizational methods determine the direction of installation, the sequence of installation of structures and the nature of their supply to the lifting mechanism (Figure 2).

When erecting one-story industrial buildings, the direction of installation is usually longitudinal. In this case, the cranes are moved along the spans, and the structures are sequentially mounted in each of them.

I -  installation of columns;

II - the same crane beams; 

III - the same truss and slabs; 

IV - the same wall panels; 1 - foundation; 2 - crane; 3 - column; 4 - crane beam; 5 - farm; 6 - wall panels

Movement of cranes and mounting positions (parking) is selected so that the crane from one position (parking) mounts as many elements as possible. So, for example, when flying 18 m and the pitch of the columns 6 m, the crane, moving in the middle of the span, can mount up to six columns from one parking lot. At span of 18, 24 and 30 m the crane must move along each mounted row during installation of columns and crane beams.

Installation of the framework of single-storey industrial buildings is usually carried out by several technological flows, each of which is intended for a leading crane, transport machines and installation equipment.

During installation from vehicles, structures are fed into spans towards installation. If necessary, local pre-assembly of structures is carried out on mobile stands moved during installation in the span.

Installation of light columns is usually carried out with preliminary laying (tops to foundations) directly at the places of their lifting. Heavy columns are laid with their base to foundations and lifted with rotation in vertical plane.

Construction of single-storey industrial buildings can be carried out simultaneously in several spans of the building by one or several simultaneously working cranes, which allows reducing the installation time of structures. However, the total number of workers and the cost of delivering cranes to the construction site and their maintenance increase.

Before installation of the columns, they are pre-laid in the crane area at an angle to the axis of the mounted row of structures and the crane motion axis. The columns are arranged equally with respect to the foundations and parking places of the crane and, if necessary, the flame is tilted from the position to the position on the rib using a U-shaped tilter (Fig. 3).

Columns begin to be mounted after acceptance of foundations or supports. When preparing columns for installation, its dimensions are checked, deviations or distortions are detected. Before lifting, the columns are exposed to the risks necessary to control their position in plan and height.

Installation of crane beams is started after installation, alignment and final fixation of columns. Concrete at the junction of the column and the foundation shell should gain 70% of design strength by this time; exceptions to this rule are stipulated in the PPM.

Beams are pre-laid in installation area on wooden liners. Before lifting the beams are inspected, dimensions are checked and hairlines are applied on the support cantilevers of the columns (Figure 4).

Crane beams are mounted by flows, sometimes installation of adjusting trusses and coating elements is included in the flow.

Trusses up to 24 m long are delivered to the object, as a rule, whole, and 30 m long or more - in the form of two or three elements, which are enlarged before installation. Trusses are mounted either directly from vehicles or with preliminary laying in cassettes in installation zone.

The trusses are installed only after installation and final fixation of all the underlying structures of the building frame. Prior to installation quality, their dimensions, location of embedded parts, as well as places of trusses support are checked.

Before lifting, the truss is lined with cradles, stairs, fixed with spacers for temporary attachment, and a safety rope, braces and braces are also fixed. Ropes and braces are tied near the ends of the truss. Spacers are fixed with screw clamps in end assembly of truss. Rope-brace is tied to second end of strut to lift strut.

Coating plates are installed, as a rule, after the next rafter truss (Fig. 5). At the same time the first plate is supplied from suspended scaffolding on columns, and the following plates - from already laid plates.

Wall panels are installed after installation of frame, in separate flow. Cranes with turret-rail equipment mounted on the basis of a crane, which combines the functions of a lifting crane and an installation platform, can be used for installation. The mounting pad can move vertically along the tower and horizontally to and from the wall. The installers, while on such site, can perform installation, reconciliation and final fixation of the wall panel.

Heat and waterproofing, sealing of joints and sealing of joints in wall panels shall be performed immediately after installation of panels from curtain scaffolding.

Define initial data for crane selection

Initial data for selection of installation cranes are dimensions and configuration of the building (dimensions of the building in terms of plan and height), its weight and location in the building of mounted structures, installation method and technology, working conditions.

For selection of boom self-propelled crane the required main operating parameters are defined: lifting capacity (Qcrtr), lifting height (Nkrtr) and hook departure (Lcrtr). The required operating parameters are determined at the lowest permissible boom departure for those structures that can have the greatest impact on the crane lifting capacity selection (column, crane beam, rafter beam, coating plate).

The mounting mass, or lifting capacity, consists of the sum of the mass of the structure itself and the equipment necessary to carry out the gripping, lifting, temporary fastening of the structure, as well as to ensure the safety and convenience of the workplace.

Determination of labour intensity and duration of installation works

The labor and machine time cost sheet is presented in Table 6. The description of the works shall fully list all conditions on which the selection of the NRR time norm according to the NRM with the corresponding unit of measurement and in accordance with the wording of the NRM depends. The NRR time norm and the composition of the link recommended in the NRR are also written out from the NRR.

The quantity of assembly elements or amount of works undertakes from tab. 1, 3 according to the unit of measure specified in ENiR.

Feasibility Study of Installation Options

On the basis of the technical and economic evaluation of the installation work options, the optimal option is chosen. The selection of a set of mounting machines for comparison and determination of the most effective is made on several sets (for example, the first set - one crane mounts all structures, the second - two or three cranes mount different structures, etc.).

The most common criterion for the efficiency of one of the sets of machines in comparison with others is the specified costs Pp, thousand rubles, in which, in addition to the cost of installation work performed by this set, the economic effect of the payback of the set for a certain time is taken into account

Determination of the composition of brigades and links

Both specialized and complex teams can work on the installation of structures.

The process of erection of building structures consists of several operations performed by performers of various profiles and qualifications (for example, installers, welders, carpenters, concrete workers for sealing joints, insulators, etc.). The work of performers can be organized in separate links and combined in time and space with the preparation of a schedule. In construction, a shift is adopted for the smallest unit of planning time. For technological and other reasons, it is not always possible to allocate a work center for a separate link for a shift. Hourly schedules are also compiled, but it is very difficult to observe them in practice, so most often brigades from performers of various profiles, the so-called complex, are organized.

The duration of the complex of works performed by the crew is equal to the duration of the lead installation facility.

In the installation process, the lead link is the installers, and according to the time of their operation - the number of machine workers - the working time of welders, concrete workers, etc.

In case n-y the assembly crane establishes several various designs with various links on ENiR, when forming for it an integrated team calculation of structure of an average assembly link

Development of a calendar plan for the construction of a one-story industrial building

The schedule (Table 8 in the Appendix) reflects the development of the installation process in time and space and is executed in the form of a linear schedule.

The name of the works or the initial data (installation of structures, termination of joints, welding, etc.), the scope of work, labor intensity, the number of machine workers necessary for the installation of structures, the composition of the performers is accepted in accordance with Table 6.

Name (type) of cranes, number of cranes are accepted on the basis of previous sections on crane selection; the number of shifts of crane operation per day (1-3 shifts) is assigned depending on the duration of work and production capabilities.

Development of safety measures during installation of precast reinforced concrete structures

All developed safety measures together with the work execution projects, as well as the process charts and other documents are located directly on the construction site. The documentation shall be carefully examined by the machine drivers and the installers performing the reconstruction of the building or structure.

When performing installation works, it is necessary to strictly observe the requirements of SNiP for labor protection in construction.

Workers between the ages of 18 and 60 should be allowed for installation work.

Workers who have worked for at least one year in installation works and have a category not lower than the third one are allowed for top-climbing works.

Drivers, welders, rafters, signalmen must undergo special training and receive a certificate.

All lifting machines shall be certified by Gostekhnadzor.

The weight of the load must be less than the lifting capacity of the mechanism (otherwise lifting must be carried out in two, three or more techniques).

The following boundaries shall be established for hazardous areas in places over which cargo is transported by cranes, as well as near buildings or structures under construction

When the structure is moved horizontally, it must be raised 0.5 m above the obstacles encountered in the path.

At wind of 1012 m/s, operations using the crane are prohibited; stop devices must be installed to prevent spontaneous movement of the crane.

All rigging devices shall be subjected to 1.25 times the limit load before operation for 10 minutes.

Slings shall be tested with a load exceeding the inventory capacity by 2 times.

All rigging devices, scaffolds, slings, as well as fences, scaffolding and lifts must be inventory and have passports.

Every day visual inspection of all devices is required.

All openings formed during construction shall be protected at the facility.

If the scaffolds are higher than 1 m, then they must have handrails and a baffle board. It is necessary to keep the structure from swinging with braces. Do not move structures after removal of gripping devices. Temporary connections, formations, conductors are removed when the joint gains the required percentage of strength (bearing joint - 70%, non-bearing - 50%). There shall be no foreign workers in the installation area. It is forbidden to transfer mounted structures over people.

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