Exchange rate as per TVZ for erection of soils structures. buildings

Contents

Space Planning Solution Analysis

Quantity takeoff

Select how to perform the work

Selection of slinging and mounting devices and equipment

Selection of installation cranes

Feasibility study for selection of set of installation cranes

Calculation of labor costs and wages

Generation of assembly flows and development of work schedule

Identification of logistical resources

Determination of techno-economic indicators

Development of safety activities

Construction plan development

Bibliographic list

SELECTION OF THE METHOD OF WORK

Installation of columns

When preparing columns for installation, the following risks are applied to them: the longitudinal axis of the column at the level of the bottom of the column and the top of the foundation

Columns are installed after they are prepared for lifting, which consists of the following:

a) the column is delivered to the installation site by means of a mounting crane and laid on wooden gaskets;

b) the columns are laid out so that the crane arm is located in a horizontal plane, and the top of the column is raised relative to the shoe;

Column slinging is performed by means of 2-branch and universal sling for crane cantilever.

Metal columns installed on foundations are fixed during installation with anchor bolts. If metal gaskets are laid under the base of the column, they must be welded. 4 plates with threaded holes for installation of bolts shall be welded to each support plate; axial hairlines shall be applied to the column branches. When the column is installed, axial hairlines on its branches are combined with hairlines applied on the support plates, which ensures the design position of the column, and it can be fixed with anchor bolts. No additional column offset is required for axis and height reconciliation in this case. After installation of braces to the mounted structures of columns and their tension, crane beams begin to be mounted. Crane beams installed at axial risks do not require additional reconciliation. After they are bolted, the braces are removed.

Installation of crane beams

Beams are laid on wooden linings at an angle to column axis during unloading. This arrangement makes it possible to inspect them and prepare the ends of the beams before starting to be enlarged and installed.

Beams are installed over the entire length of temperature block. After temporary attachment mark of their top on supports is checked. If the deviations exceed 5 mm compared to the highest elevation, steel gaskets are laid under the remaining supports of the beams.

Pre-attached or hinged stairs-platforms are attached to columns. At the same time, the installers clean the beams from dirt, secure the safety rope and prepare the tool. Then, tying the braces, the beam is slung. At the signal of the installer foreman, the driver lifts and supplies the beam to the installation site; installers by means of braces give the beam close to the design position, keeping it at a height of 15 cm from the support surface. Installers standing on staircases, guided by risks, set the beam in the design position. After checking the correct position of the beam in the plan, it is fixed with four bolts. After that, according to the signal of the foreman, the driver eases the tension of the sling branches and the installers disassemble the beam, and the foreman once again checks the correctness of its fixation. At this time, the other two installers prepare the next beam for lifting.

Device for adjustment of crane beams. The device includes three pairs of replaceable racks. Adjustment of crane beams by means of device is performed by two installers. First, the device is installed with a mounting crane on the end of the crane beam. Device is moved along beam on rollers manually by means of rope.

For beam alignment device is installed on column cantilever and fixed with safety chain. The upper belt of the beam is gripped by the adhesive hooks of the device. The beam is offset in height and plan using a jack and a horizontal screw. At the end of alignment, liners are laid under the beam and fixed with anchor bolts. Then crossbeam is lowered, hooks are disengaged, device is lifted and rolled on rollers along beam to next column.

Installation of coating

Prior to erection of metal rafter trusses and reinforced concrete slabs, the following works shall be performed:

- all work on the underground part has been completed;

- temporary roads have been laid;

- columns are installed;

- all necessary materials and products for installation works have been received and delivered;

Preparation of the truss for installation consists of the following operations:

- pre-assembly,

- arrangement with cradles, stairs and bracing,

- slings,

- lifting to the installation area,

- turning by means of braces across the span,

- temporary attachment using conductors, braces, struts between trusses and braces.

Position of truss is adjusted by position of axial hairlines on ends of truss.

Slinging and lifting of the rafter truss are carried out using a universal traverse, and coating plates - using a four-branch sling.

The mounted first rafter truss is parted in two places before it is disassembled. The braces are attached on one side to the bottom of the mounted columns of this span, and on the other side to the ground anchors.

The second and subsequent trusses are mounted together with two spacers, by means of which a mounted truss with a previously mounted one is fastened. Inventory spacers, safety cable, sling cable are attached to the farm before it is lifted. Spacers, safety cable are removed during installation of coating plates.

When laying in each cell of the first plate, one installer is on a plate laid in an adjacent cell, the second - on a ladder platform hung on a column. In the future, both installers switch to the newly laid plate for laying the next one. Extreme coating slabs during installation shall be equipped with inventory enclosures.

Hinged platforms and stairs are used for maintenance of installation works, lifting of installers to installation units.

After the position of the metal rafter truss is adjusted and fixed to the design position, disassembly is carried out.

Fixation of coating plates is performed by electric welding of embedded parts of plates and beams (trusses) of coating in at least three corners. The plate is welded immediately after installation. Welded elements of structures are pre-cleaned from solution, rust, paint, fat stains, other contaminants and dried.

Corrosion protection coating (galvanizing of welds) and embedded parts sections is performed in all places where the factory coating is broken during installation and welding.

The sealing of the seams of the coating plates is carried out by means of a mobile installation. As a feeder, a syringe is used, which is loaded with a dry mixture of cement, sand and crushed stone, using a skip lift. Compressed air for the syringe machine and water supply to the working member is supplied from the compressor .

Installation of external walls

Installation of walls is carried out independently after the assembly of structural elements of the frame and coating on the grip (usually within the temperature seam). Panels are installed by means of cranes on caterpillar or pneumatic wheel travel with straight booms.

Installation of wall panels is provided on the bed from finished mortar with simultaneous laying of beacons, if necessary, and temporary attachment with struts or struts.

Scope of work:

- arrangement of bed from solution with beacon laying (strength of material from which beacons are made should not be higher than the design-established compression strength of the solution used for the bed device).

- lifting and installation of panels.

- verification and temporary fixation.

-supplating of horizontal seam with mortar.

- removal of temporary attachment.

Wall panels are mounted between columns to the entire height of the building. Installers align and attach the installed panels from the inside of the building using a welding apparatus. If it is possible to travel inside the building, it is advisable to use two car-based lifts as workstations for installers. This allows the installers to accept each panel at its column connections. Pouring and sealing of joints is performed immediately after installation of panels and welding of joints.

When installing the external walls of buildings, the accuracy of installation in connection with the performance of wall panels of enclosing functions and from an aesthetic point of view is of particular importance. Therefore, it is necessary: to observe the dimensions of the joints, the proper quality of their sealing, to maintain the integrity of the faces of the face surfaces.

Welded joints of metal structures

Mounting joints of steel structures are welded, on bolts.

The welded joints of the mounting elements are initially fixed to each other with coarse mounting bolts, and since the obtained strength is not sufficient in terms of strength calculation, the elements are welded to each other. Depending on the type of structure to be connected, the elements can be welded directly or using additional butt straps.

Column joints

Columns with a height of 18 m or more before transportation are divided into sending elements, based on the dimensions of vehicles. During installation, these parts of the columns are joined together, welding can be carried out directly or with the help of steel pads, which are installed on bolts and welded to the connected elements. The joints of columns of single-story industrial buildings are usually made in the above-crane part above crane beams. Milled ends of above-crane and main parts of column are joined to each other and welded along plane of joint. For greater stiffness, both parts are connected to each other by a butt plate strap.

Connection of crane beams with columns

The crane beam rests with the edge of the vertical sheet directly on the support plate of the column and is bolted to it. Additionally, the crane beam is attached to the above-crane part of the column by brake structures, which are attached to the columns and beams on bolts and additionally welded with an extended seam.

Connecting trusses to columns

When the truss is hinged to the column, the upper truss belt is attached to the column, connecting the profile with bolts and a mounting weld to plates welded to the column. Lower girder belt is shaped to rest on mounting table and attached to column by bolts and welding.

Bolted connections of metal structures

Bolted joints of steel structures depending on the design of the connection and perceived loads are made on bolts of coarse, normal and increased accuracy and on high-strength bolts. Coarse and normal precision bolts are not used in cut connections.

Holes for such joints are drilled or pushed. The diameter of the hole is larger than the diameter of the bolt by 2... 3 mm, which greatly simplifies the assembly of connections. At the same time, the deformation of the connection is significantly increased, therefore, bolts of coarse and normal accuracy are used to fix the connections directly resting one element on another, in the units of force transfer through the support table, in the form of strips, as well as in flange connections.

Bolted connections of higher accuracy are used instead of rivets in hard-to-reach places where it is almost impossible to install rivets. The diameter of the hole in the connections on such bolts may be greater than the diameter of the bolts by no more than 0.3 mm. Negative tolerance for holes is not allowed. The bolts in such precise holes sit tight and perceive shear forces well.

Connections on high-strength bolts combine ease of installation, high bearing capacity and low deformation. They are shear resistant and can replace rivets and bolts of increased strength in almost all cases.

Based on the analysis of space planning and structural solutions:

1) divide the building into 5 installation sections, each of which is limited by the span width and the length of the temperature unit.

2) we adopt the following methods and methods of erection of structures:

- in the direction of installation flow development - longitudinal;

- according to the sequence of components installation - combined:

- column, crane beam, wall panel - differentiated method;

- coating - complex;

- according to the sequence of building erection by height - build-up;

- according to the method of bringing structures to design position - limited-free;

- according to the method of preparation of structures for installation - with preliminary layout

Construction plan development

Construction plan for installation works is a plan of the construction site with designation of the diagram of the building under construction, diagram of the movement of installation cranes with parking lots and areas of operation, areas of preliminary layout of structures and temporary roads.

The territory of the construction site must be fenced with a gate at the entrance and exit. During the development of the construction plan, it is necessary to solve the issue of determining the crane coverage areas and the arrangement of temporary roads.