The Employer shall provide assistance to the Contractor in obtaining necessary approvals.

 

Performance of earthworks in the area of existing underground communications shall be executed under direct supervision of a foreman or supervisor, and if earthworks are performed in the protected live cables area, or in the existing gas pipeline area, addition supervision of electric or gas facilities employees is required.

If during earthworks or construction works, archaeological or historical arte facts are discovered, the Contractor shall stop further performance of works and within a day shall report about these findings to the appropriate authority for protection of cultural heritage and local authority in whose territory earthworks are performed.

If during earthworks it is determined that groundwater level does not match the design data, the Contractor shall notify the Employer about this and take measures to resolve the situation.

Backfilling of trenches shall be performed with layer-by-layer compaction. Layer thickness shall be not more than 200 mm.

Excessive and unusable soil excavated from pits and trenches shall be moved to places of laying, not allowing temporary dumps.

Technical quality control of earthworks shall be carried out during construction.

During acceptance of trenches and pits, compliance of their location, size, elevations, slope and soil composition of the foundations shall be verified for compliance with the project requirements.

 

Concrete Works

Mixes and aggregates

 

a) The choice of cements for making concrete mixes shall be made in accordance with therequirements of:

• SNiP 3.03. 01 -87 "Bearing and guarding structures";

• GOST 23464-79 "Concretes. Classification”

b) Acceptance of cements shall be performed according to GOST 22236-85 "Cements.

Acceptance rules".

c) Transportation and storage of cements shall be performed according to GOST 22237-85"Cements. Packing, labelling, transportation and storage".

d) Concrete mix composition, preparation, acceptance rules, control and transportation methodsshall comply with GOST 7473-85 "Concrete mixes. Technical conditions".

e) Concrete aggregates shall be factional and washed. Applying of natural mixture of sand andgravel without size grading is not allowed.

 

 

Casing

 

а) The Contractor shall use timbering types in accordance with GOST R 52085-2003 "Timbering. Terms and Definitions".

b) Installation and acceptance of timbering, dismantling of cast-in-situ structures, cleaning and lubrication of timbering shall be made as per the project of performance of works.

c) The following measures shall be provided during installation of timbering:

- required durability, rigidity and invariability under the influence of technological loads, andlow adhesion to concrete;

- given accuracy of sizes of structures erected inside timbering and correctness of structureslocation in space;

- possibility of rapid assembly and disassembly without damaging the concrete structure beingbuilt;

- unhampered installation of reinforcement, embedded items, laying and compaction ofconcrete mix;

- required density in interfaces between individual elements, excluding laitance leakage andformation of build-ups;

- availability of compensators that reduce thermal stresses in timbering during concreteheating;

- possibility of timbering heat insulation or installation of heating elements inside timberingduring concrete works in winter conditions.

d) During acceptance of installed timbering, supporting structures and fastenings, it is necessary tocheck:

- bearing timbering and its supporting structures;

- correct arrangement of timbering supporting structures, as well as rigidity and invariability ofthe entire timbering in general;

- correctness of timbering installation, caps, embedded items.

 

Reinforcement and embedded items

 

а) During installation of reinforcement and embedded structures, it is necessary to:

- perform checking of timbering and eliminate detected defects;

- perform assembly of reinforcement and embedded items in sequence, which ensures their correct (designed) position;

- provide required gap for formation of protective concrete layer between reinforcement and timbering, by fastening of the corresponding fixtures on reinforcement;

- fix the assembled reinforcement and embedded items to prevent their shifting during concrete casting.

 

Anchor bolts

 

Pins for anchor bolts, nuts and washers shall be m ade of the steel grades, the mechanicalproperties of which are not worse than steel grade St3 as per DSTU 2651:2005 (GOST 380-2005) "Carbon steel of ordinary quality. Grades".

 

Concrete casting of structures

 

а) Prior to packing of concrete, all structures and their elements, to be covered during subsequent performance of works (reinforcement, embedded items) shall be accepted with issuing the examination report on covered-up works.

b) Concrete shall be laid in the concrete casting structures by horizontal layers of equal thickness without gaps, with consistent direction of laying in the same direction in all layers.

c) During compaction of concrete, it is not allowed to rest vibrators on reinforcement and embedded items.

d) Protective layer of concrete for the main reinforcement shall provide joint operation of reinforcement with concrete at all stages of structure operation, as well as protection of there inforcement from external environment and temperature effects.

 

Foundations

All types of foundations must be factory-made and presented to the Employer for approval.

The Employer shall ensure the delivery of foundation blocks from the factory to the storage or the place of installation.

Before installation of foundations Contractor shall make covered-up works report in accordance with requirements DBNA.3.1-5-2009 «Arrangement of construction production».

 

Covered-up works and covered-up works reports

The erection works for over ground structures shall commence only after arrangement of the underground structures, soil backfilling in pits cavities, trenches and site layout.

Covered-up works are subject to inspection with issue of covered-up works reports in accordance to DBN A.3.1 -5-2009 “Arrangement of construction production”.

 

 

Erection works

At the site where assembly work shall be performed, performance of other works and presence of strangers are not allowed.

Methods of slinging of structures and equipment elements shall ensure their delivery to the installation site, in the position corresponding to installation.

Cleaning from dirt and ice of structural elements subject to installation, shall be made prior to their lifting.

Slinging of structures and equipment shall be made by the load-handling devices, which meet there equirements of GOST 24259-80 "Installation accessories for temporary fastening and alignment of building structures".

The elements of assembled structures or equipment during transportation shall be held from swayingand rotating by means of flexible guy lines.

When moving structures or equipment, the distance between them and projecting parts of assembled equipment or other structures shall be not less than 1 m horizontally, and 0.5 m vertically.

The angles of deviation from the vertical of the load ropes and polyspasts of load-lifting facilities(mechanisms) during installation shall not exceed the value specified in the technical requirements for this load-lifting mechanism.

Removal of slings from structure and equipment elements installed in the design position shall bedone after their permanent or temporary safe fastening.

Before performance of installation works, it is necessary to determine the procedure of exchange of prearranged signals between a supervisor and load-lifting mechanism's operator.

Assembly of structures shall be done only using parts and components that have been cleared from burrs, dirt, oil, rust, moisture, ice and snow. During assembly, change of design of parts and structures is not allowed.

Designed fastening of structures with bolted erection joints shall be implemented right after instrumental verification of position accuracy and alignment of structures.

All mounting holes shall be made according to the design diameter and only at the metal ware factory, with the exception of holes specified by the installation technology.

Structures with welded field connection shall be fastened in two stages, temporarily for the first time, and then as per the design.