J.1.6_Demolition_and_Construction_Site_Conservation.pdf

A-E_SERVICES_CMR_ DEMOLITION_&_CONSTRUCTION_ SITE_CONSERVATION

SARAJEVO, BOSNIA&HERZEGOVINA

BOOK 4

4.3.1 Technical description

4.3.2 Calculations

4.3.3 Drawing

S 01 Pinciple of slope stability with characteristic cross section 1:200

S 02 Demolition site plan 1:200

S 03 New construction site layout – I PHASE (Object demolition) 1:200

S 04 New construction site layout – II PHASE (Slope stability) 1:200

S 05 Stage 1a – Demolition of the slab at elevation +7.40m 1:100

S 06 Stage 1b – Demolition of the slab at elevation +3.70m 1:100

S 07 Stage 1c – Demolition of the slab at elevation +0.00m 1:100

S 08 Stage 1c – Demolition of the slab at elevation +0.45m 1:100

S 09 Stage 2a – Demolition of the slab at elevation +11.40m 1:100

S 10 Stage 2b – Demolition of the slab at elevation +7.40m 1:100

S 11 Stage 2c – Demolition of the slab at elevation +3.70m 1:100

S 12 Stage 2d – Demolition of the slab at elevation +0.00m 1:100

S 13 Stage 3a – Demolition of the slab at elevation +11.40m 1:100

S 14 Stage 3b – Demolition of the slab at elevation +7.40m 1:100

S 15 Stage 3c – Demolition of the slab at elevation +3.70m 1:100

S 16 The principle of cutting and dismantling structural elements 1:50

Part 3 DEMOLITION & CONSTRUCTION SITE CONSERVATION

4.3.1 TECHNICAL DESCRIPTION

TECHNICAL DESCRIPTION

The RAA building in Sarajevo, Alipašina 43 street (hereinafter referred to as the Building) has floor plan dimensions of maximum length 25.80 m, maximum width 30.80 m and variable number of stories (basement and two stories or only basement).

The building was erected in at least two phases - blocks. In the first phase, it was a residential building with cascade structure on a gentle slope. The building was constructed as a mixed structural system with the elements: concrete foundations, columns, horizontal tie-beams and vertical tie-columns with 12, 20 and 25 cm thick brick walls plastered on both sides, and slabs. The new building was constructed of reinforced concrete foundations, reinforced concrete walls, and reinforced concrete slabs.

GENERAL

A request was set to prepare a Demolition design of the Building with the goal of constructing a new building in the vacated space.

The Contractor shall, at all times during his work and stay on the construction site, keep the working place and the associated roads and passages clean and free of any trash, waste and debris. All areas where works are executed and communications must be safe.

During the work, the installations that remain in use due to the functional needs of the location, as well as the parts of the facilities that are not subject to removal, will be visibly marked.

All buildings must first be cleaned of destroyed and leftover items and any remaining debris.

All adjacent buildings are far enough away from the Building that will be removed and they are not in danger of collapsing. The preservation of stability of a slope within the location that may be endangered by the removal of the Building, but also potentially endangered by damage to installations and the existence of adjacent structures is given in a separate section.

Careful and professional demolition procedures eliminate the possibility of damage to neighboring buildings that have not been treated by this demolition project.

If problems arise during the removal of the Building, the Contractor must immediately notify the Investor in order to find a solution for securing neighboring building.

In order to safely remove the building and perform demolition work, the Contractor will perform all necessary actions and safety measures (scaffolding, supports, temporary supports, protective barriers, etc.) defined by the Occupational Safety Study which will protect staff working on demolition, as well as other participants at the construction site, from objects falling from heights.

The contractor must organize the works in such a way as to meet the provisions of the relevant institutions regarding noise, dust, dirt, dispatch of materials as well as maintaining the cleanliness of urban and suburban roads.

All possible passages of heavy machinery over surfaces with insufficient bearing capacity must be secured against damage.

Before starting the demolition, the contractor must be well acquainted with the position of above-ground and underground installations of electricity, gas, telephone, water, sewage, etc.

The demolition of the building must not be started until all the necessary preparations have been made, including necessary unloading of structure or possibly the strengthening in certain places.

Any removal of a load-bearing element that could compromise the stability of another element requires the simultaneous demolition of both.

Loose parts of walls or slabs must be immediately demolished continuously until a stable entity is formed in order to prevent self-collapse.

In particular, loading, unloading etc. must not be performed around a part of the loose structure.

Shredding of already demolished parts will be done off-site, and before the final treatment of the waste material.

The preparation of the Construction Site Organization Project, Waste Management Study, Occupational Safety Study, Fire Protection Study and others are integral parts of the Quality Management Project, as well as other construction site documentation required by regulations, is the responsibility of the Contractor, which will be approved by the Investor.

It is forbidden to perform several work operations in the same place.

The equipment of the construction site, as well as the insurance of individual devices, machines and workers on it during demolition and dismantling, must fully comply with the regulations.

The Contractor is obliged to provide appropriate machines, workers and materials for the demolition of the Building.

Disposal of materials should be carried out according to the planned order in the available space in order to avoid additional internal transport, noise, dust, etc.

Material created by dismantling, demolition, etc. should be disposed of according to the type of treatment defined in the Waste Management Study and free space should be provided for access to vehicles that take separated waste to the intended treatment and storage.

Loading/unloading areas are considered to be all those places where any loading or unloading will take place. In this case, these are the roads and the space around the building inside the construction site fence.

Construction materials are not allowed to be deposited on scaffolding and platforms for which there is no evidence of load-bearing capacity.

If during the removal of the building materials of unknown content are found, it is necessary to inform the Investor and the relevant inspections in order to determine what kind of materials are in question, and to anticipate an adequate method of disposal.

In the case of materials containing harmful substances, disposal must be carried out by authorized companies.

The construction waste material is shredded on the construction site only to the size necessary to be manipulated on the construction site, and shredding to a size suitable for final disposal will be performed at the site provided by the Contractor.

When collecting and disposing of construction waste, it is necessary to carry out its preliminary rough sorting and shredding to a transportable size.

The organization of technological flows and procedures for obtaining crushed material will be performed in two steps:

• initial comminution of structural elements during removal to transportable size

• by using tools that crush concrete and cut reinforcement into pieces smaller than 40 cm. All allocated raw materials as well as unusable waste are taken care for by the Contractor in accordance with the relevant regulations.

In accordance with the applicable legislation, especially with regard to environmental protection, it is necessary that all contractors, regardless of which part of the disposal process they participate in, achieve the basic objectives of waste management:

• Avoidance and reduction of waste generation and reduction of hazardous properties of waste whose generation cannot be prevented,

• Utilization of valuable properties of waste for material and energy purposes and its treatment before disposal,

• Disposal of only that part of waste that cannot be used in places provided for by law,

• Avoid environmental pollution: water, soil and air above the prescribed limit values,

• Perform work in such a way as to avoid danger to human health,

• Perform work in a safe manner without endangering people, equipment, facilities and property.

The applied method of demolition without excessive vibrations, sudden shocks, etc., and respecting the laws of the designed static system and the laws of the profession, ensures the stability of the remaining parts of the building and the soil. This also protects people outside the designated work area, and in the work area with the application of prescribed safety measures at work.

DESCRIPTION OF THE DEMOLITION TECHNOLOGY OF THE LOAD BEARING STRUCTURE OF THE

BUILDING

Before starting to cut horizontal and inclined reinforced concrete structural elements, it is necessary to remove the linings from the upper and lower side of the slab. The roof slabs from above should be freed from the gravel layer, the protective layer and the waterproofing, with the separation of differently treated materials during disposal at the temporary landfill. Other reinforced concrete slabs on the upper side should be freed from wooden, stone or ceramic floor layers to the level of the upper screed level.

The slabs on the underside should be free of all elements that are bolted on or can be uncontrollably separated from the slab during cutting and vertical transport, while the mortars do not have to be removed beforehand.

Conventional methods of demolition of concrete are based on classic jackhammering with pneumatic hammers and tools operated by workers and cutting of reinforcement with devices for cutting reinforcement (burners, autogenous devices or cutting plates). These methods of demolishing concrete require a large amount of labor and a large consumption of pneumatic and/or electric tools and accessories. During the work quite a lot of noise and dust is produced. Having this in mind and the environment in which the building is located, these methods will be applied to demolish only those elements where it is not possible to apply modern methods of cutting concrete, namely columns and walls. In doing so, constant local wetting of the jackhammering point will be performed to prevent the formation of dust.

Machine cutting of concrete is done with machines that have discs with diamond crowns and that are highly productive and quiet. For cutting concrete, these machines use a wet process to cool the cutting discs, which eliminates the possibility of dust, which is very important in this case. Having in mind the great advantages of machine cutting of concrete, this method will be applied for cutting all horizontal elements of the structure of the building (slabs and beams). The operation of the concrete cutting machine requires a connection to a source of electrical energy and a constant supply of water.

Having in mind the environment in which the building is located and the load-bearing structure, the method and technology of demolition by cutting, supporting, loading and transporting parts of the load-bearing structure to a temporary landfill have been developed. Processing and shredding is performed at the landfill outside the construction site, which is provided by the Contractor. Finally, the material is transported to a permanent landfill.

Cutting and removal of parts of the structure of the building will be done according to the principle "FROM THE TOP DOWN", ie. in the reverse order of construction order.

For cutting individual parts of the structure, conventional methods of local demolition of concrete using pneumatic and/or electric pichammers and cutting of reinforcement with reinforcement cutting devices are envisaged. Most of the construction will be cut using high-performance concrete cutting machines with diamond crown discs.

Demolition of reinforced concrete slabs Horizontal (ceiling) and inclined (stairs) reinforced concrete slabs must be supported before cutting so that the cut piece of reinforced concrete slab does not fall on the structure below after release. Cutting of reinforced concrete slabs is done in two phases. The first phase of cutting is done along the bearing direction of the reinforced concrete slab at intervals of 2m, provided that the last strip of the slab must also not be wider than 2m. The second phase is cutting perpendicular to the cutting line in the first phase by cutting one segment at a time. The next segment is not cut until the previous one is completely removed. The length of the segment depends on the length of the transport trough and the ability of the crane to lift the cut element at a specific place. Accordingly, it is necessary to arrange the supports under the slab so that, before the final release of the element, at least two holes with a diameter of 30 mm are drilled and hooks are placed for lifting according to the sketch (slot of the fourth line of the rectangular element /2m x free x slab thickness/ according to the sketch).

To prepare the slab and the wall, at least two holes with a diameter of 30 mm are drilled in the segments and hoops are placed in them for lifting according to the sketch.

As already mentioned, before starting to demolish the slabs, it is necessary to support each strip of slab between the beams and/or walls in such a way as to ensure the possibility of cutting the slabs into strips and segments. It is then necessary to ensure that the segments can be safely removed to the construction site from where they are removed to the landfill provided by the Contractor. The project envisages that the maximum dimensions of a piece of slab are 2m x free x slab thickness.

In the same way, flights of stairs with intermediate landings are demolished. By controlling the maximum weight of the cut RC element, it is envisaged that according to the attached table, a support is selected whose load-bearing capacity with extension to the required length must not be less than 20.0 kN for axail pressure. The struts are stiffened in a plane below the slab by tubular scaffolding and fastened to a beam or wall along the perimeter of the slab field that is next in demolition process to prevent horizontal movement of the support system.

When the two hoops are installed, the element is picked up by a car crane that is able to lift a load of at least 50 kN at that point and slightly tighten the lifting cables. Then the second phase of cutting of the element carried by the car crane is performed. After the RC element is released, it is immediately removed and disposed of at the construction site. It is important to say that under no circumstances should the RC element be cut, which is released from the rest of the RC structure, if at least two hoops are not placed in that element and the support is performed with the equipment for removing RC elements. The edge bearing elements (which provide supports) on all sides of a slab must not be removed until the complete considered field of the slab is removed by primary and secondary cutting.

Before starting to cut the slabs of the first stage, it is necessary to support the slabs at all elevations.

Support strips has to be at leest 1m wide and should be between two stages but on the side of the stage which does not cutting at that moment.

Demolition of reinforced concrete beams

Beams can only be removed when the slab on both sides of the beam has been removed. Before removal, the beams are supported with props whose distance must not exceed 100 cm. The beams are cut by secondary cutting with prior drilling and placement of hoops before releasing the cut element from the rest of the structure. The distance between the secondary cutting lines must not exceed 200 cm.

Demolition of reinforced concrete and masonry walls above reinforced concrete slabs The masonry walls of the building are demolished by classic jackhammering with pneumatic hammers and tools handled by workers. Reinforced concrete horizontal and vertical tie-beams of these masonry walls are also demolished with pneumatic hammers and tools used by workers to cut the reinforcement with reinforcement cutting devices (burners, autogenous devices or cutting discs).

Demolition of reinforced concrete walls is also done in two phases. The first phase of cutting is done vertically at a distance of no more than 200cm. The second phase of cutting, ie horizontal cutting, is done mostly at free height, having in mind the ratio of the weight of the element and the load-bearing capacity of the crane at that location, with at least two hoops in the holes and tightening the cables to lift the cut piece according to the sketch.

The walls can only be removed when the slab on both sides of the wall has been removed.

Demolition of reinforced concrete columns above reinforced concrete slabs The demolition of columns is done in the same way as the demolition of the walls in the second phase.

The second phase of cutting is performed by pre-drilling holes and supporting the element before the final separation from the rest of the structure at free height, having in mind the ratio of the weight of the element and the load-bearing capacity of the crane at that location. It is first necessary to place at least two hoops in the holes and tighten the cables to lift the cut piece of the column according to the above sketch.

Demolition of foundations, walls and columns at the ground floor

When the last slab above the ground is removed in each of the demolition phases, other structural elements are demolished by conventional demolition methods (already described in the text) and/or heavy construction machines (excavators, loaders and dozers). When demolishing with machines, such as tracked or wheeled excavators with a hydraulic bucket or various types of dozers with or without a ripper, the machine must be at a distance of 1.5 x H where H is the height of the part of the building being demolished by the machine. The breaking strength of the steel rope used to transmit the traction force of the machine required for demolition must be at least three times greater than the traction force. The traction power of the machine must be transferred to the collapsing part of the Building as evenly as possible, and suitable pads must be placed for this purpose. Extraction of buried bulky broken pieces or steel elements of the collapsed structure with the help of machines is allowed only after they are completely freed from other pieces and dusty material above them. The use of tractors with wheels for demolition and (or) extraction of heavy parts of the building is prohibited. It is also forbidden for machines to move on the slabs and ramps of the building without proper control of the load-bearing capacity of the slabs or ramps.

The selected demolition crane is LTM 1050-3.1 with technical characteristics as follows:

Main designer :

Fa di l Bi be rki ć di pl.i ng.građ

4.3.2 CALCULATIONS

Control of slab support safety during demolition:

Existing shape:

Slab above the first floor

Lower reinforcement zone in the field of slab 20/12,5

Upper reinforcement zone in the field of slab 12/25 - constructive reinforcement

Slab above the second floor

Lower reinforcement zone in the field of slab 20/12,5

Upper reinforcement zone in the field of slab 12/25 - constructive reinforcement

Table of materials

Load:

Weight of the plate to be cut q = 0,2 * 25 = 5,00 kN/m2

Weight of equipment and people 2,00 kN/m2

Weight of undisassembled panel linings 1,00 kN/m2

Total: 8,00 kN/m2

Applied: 10,00 kN/m2

Force on one Support:

N = (2 x 2 x 10) / 4 = 10 kN N = (2 x 1,25 x 10) / 4 = 6,25 kN

Input data - Structure

No Material name E[kN/m2] μ γ*kN/m3+ αt*1/C+ Em[kN/m2] μm 1 Beton MB 30 3.150e+7 0.20 25.00 1.000e-5 3.150e+7 0.20

Isometric

<1> 0.200 0.100 1 Thin slab Isotrophy

Beam sets Set: 1 Section: b/d=50/50, Approx. eccentricity

Mat. A1 A2 A3 I1 I2 I3

1 - Beton MB 30 2.500e-1 2.083e-1 2.083e-1 8.802e-3 5.208e-3 5.208e-3 α No t[m] e[m] Material Analysis type Orthotropy E2[kN/m2] G[kN/m2]

Input data - Load

Design (concrete)

Minimum required lower reinforcement zone in the field of slab 3,09 <<<< 25,18 cm2/m

Conclusion:

The proposed support of the slab before demolition satisfies the safety against demolition

4.3.3 DRAWINGS

UNCLASSIFIED

30.07.2022.

Edhem Živalj d.i.g.

Hajrudin Hadžiabdić d.i.g.

(Seal)

Phase

Project Number

Classification

Checked By

Drawn By

CADD File Name

OBO Project Number

CADD Plot Scale

Date

Drawing Scale

Number

35%CONCEPT

Sheet

60% 100%90% FINAL

Release For Construction:

Drawing Title

OBO/PDCS/PDC OBO/PDCS/DE

OVERSEAS BUILDINGS OPERATIONS

United States Department of State

Washington, D.C.

DescriptionRev Number

Revisions

Date

SARAJEVO

projektovanje, inžinjering, konsalting Srđana Aleksića 14 tel/fax: 033 213 840

FABING d.o.o.

Fadil BiberkićPrincipal

A-E_SERVICES_CMR_

DEMOLITION_&_CONSTRUCTION_

SITE_CONSERVATION

BOSNIA&HERZEGOVINA

SARAJEVO

projektovanje, inžinjering, konsalting Srđana Aleksića 14 tel/fax: 033 213 840

FABING d.o.o.

S16

1 : 50

1) CUTTING OF

HORIZONTAL

REINFORCED CONCRETE

SLABS

SEGMENTS:

1,2,3,4,5,7,9,10,11,12,13,14, 15,16,17,19,20,22,23,24,25, 26,27,28,29,30,31,33,34,36, 37,38 and 39

Segment mass - G ‹ cca 5t

2) CUTTING OF

HORIZONTAL

REINFORCED CONCRETE

BEAMS IN x DIRECTION

SEGMENTS:

6,8,18,21,32 and 35

Segment mass - G ‹ cca 5t

3) CUTTING OF

HORIZONTAL

REINFORCED CONCRETE

BEAMS IN y DIRECTION

SEGMENTS:

40,41,42,43,44 and 45

Segment mass - G ‹ cca 5t

MOUNTING

SLAB

SEGMENT

d e p e n d i n g o n t h e t h i c k n e s s o f t h e p l a t e min 30cm min 30cm n o t m o r e t h a n c m arbitrary dimension

HEAVY DUTY ANCHOR WITH HOOKS

FOR LIFTING Ø24mm class 8.8

WITH ANCHOR PLATE DIMENSIONS

200x200x20mm AND SCREW NUT

M24 class 8.8, IS PLACED IN DRILLED

HOLES Ø30mm IN THE INDICATED

PLACES BEFORE SLICING SLABS

DETAIL OF SLAB SEGMENT DISASSEMBLY

B E

A M

B E

A M

BEAM

BEAM

FIRST PHASE OF CUTTING

REINFORCED CONCRETE SLABS

S E

C O

N D

P

H A

S E

O

F

C

U T

T I N

G

R E

I N

F O

R C

E D

C

O N

C R

E T

E

S

L A

B S

THE PRINCIPLE OF CUTTING A

HORIZONTAL STRUCTURAL ELEMENTS

B E

A M

B E

A M

BEAM

BEAM

THE PRINCIPLE OF SUPPORTING SLAB

BEFORE CUTTING

SUPPORTS UNDER THE SLABTUBULAR SCAFFOLDING

B B

B B

D I R

E C

T I O

N

O

F

D E

M O

L I T

I O

N

SECTION B-B

B B

273334 20 19 12 7 24144

TUBULAR SCAFFOLDING SUPPORTS UNDER THE SLAB

FIRST PHASE OF CUTTING

REINFORCED CONCRETE SLABS

THE PRINCIPLE OF CUTTING A

VERTICAL STRUCTURAL ELEMENTS

wall segment max 2.0 m u p p e r p h a s e o f w a l l d i s m a n t l i n g l o w e r p h a s e o f w a l l d i s m a n t l i n g w a l l s e g m e n t m a x m

FIRST PHASE OF CUTTING

REINFORCED CONCRETE WALL

Slab segment for lifting and transporting

Beam segment (x direction) for lifting and transporting

Beam segment (y direction) for lifting and transporting

Wall/Column segment

(in floor plan) for lifting and transporting

Wall/Column segment

(upper phase) for lifting and transporting

Wall/Column segment

(lower phase) for lifting and transporting

THE PRINCIPLE OF CUTTING

AND DISMANTLING

STRUCTURAL ELEMENTS

AutoCAD SHX Text WARNING: This document is the property of the U.S. Government. Further reproduction and/or distribution outside the contractor team is prohibited without the express written approval of: U.S. Department of State ATTN: Washington, DC 20520