final year project

RETROFIT OF EXISTING TWO STOREY STRUCTURE WITH

THE FUTURE PERSPECTIVE OF ADDING AN ADDITIONAL

STOREY

George Georgiou Ch. (5583)

A Project Report

submitted in partial fulfillment of

the requirements for the degree of

BSc Civil Engineering

Supervisor: Dr. Petros Christou

Department of Civil Engineering

Frederick University

December 2013

DECEMBER 2013

Da Vinci Vitruve Luc Viatour

George Georgiou Ch. - Static Equilibrium of an existing two storey structure with the future

January 2014 Perspective of adding an additional storey -

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Acknowledgment

This project would not have been possible without the support of many people. First, I would

like to thank my supervisor, Dr. Petros Christou for his valuable guidance and continuous

advice and support. I would also like to thank my family, for their support, patience and

understanding in the course of this three year study; special thanks to my wife Elena, my

baby-girl Mary- Angeliki, my mother-in-law Mary, my colleague Mr.George Georgiou and my

boss Mr. Christos Koupparis and his company C. KOUPPARIS AND ASSOCIATES. All of the

above have been providing me with the requisite moral support to continue and complete this

course. Furthermore, I would like to thank my friend and classmate Mr. Sokratis Lambrou for

his guidance in connection with the application of the software STEREOSTATIKA .

Finally, I would like to thank the committee responsible for this Project namely: Dr.

Petros Christou, Dr. Demetris Nicolaides and Dr. Michael Antonis.



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Table of Contents

Chapter 1 .................................................................................................................................. 10

1.1 Introduction ...........................................................................................................................10

Chapter 2 .................................................................................................................................. 12

2.1 Description of the existing building .....................................................................................12

Chapter 3 .................................................................................................................................. 16

3.1 Literature Review .................................................................................................................16

3.1.1. Retrofitting of a medieval bell tower ..................................................................... 17

3.1.2. Underwater pre-stressed piles repair ................................................................... 19

3.1.3. Retrofitting of hollow bridge piers ......................................................................... 20

3.1.4. Strengthening of R.C. beam – column joints ........................................................ 21

3.1.5. Concrete confined with FRP tubes ....................................................................... 23

3.1.6. Heritage university building .................................................................................. 23

3.1.7. Arresting leakage in Muran dam .......................................................................... 24

3.1.8. Reinforced Concrete jacketing ............................................................................. 24

3.1.9. Examples of repairing structural elements with the use of jacketing: .................... 29

3.1.10. Decision of retrofit method ............................................................................... 37

Chapter 4 .................................................................................................................................. 38

4.1 Methodology .........................................................................................................................38

Chapter 5 .................................................................................................................................. 43

5.1 Analysis and Results ..........................................................................................................43

5.1.1. Data collection ..................................................................................................... 43

5.1.2. Procedure - Evaluation of Data ............................................................................ 44

5.1.3. Output - Results ................................................................................................... 46

5.1.4. Final Results: ....................................................................................................... 51

Chapter 6 .................................................................................................................................. 52

6.1 Discussion ............................................................................................................................52

6.1.1. General Conclusions .......................................................................................... 53

Chapter 7 .................................................................................................................................. 55



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References .......................................................................................................................................55

APPENDIX - A .......................................................................................................................... 56

Solutions for the rest of Columns ...................................................................................................56

For 1C4:............................................................................................................................. 56

For 1C5:............................................................................................................................. 57

For 1C6:............................................................................................................................. 58

For 1C7:............................................................................................................................. 59

For 1C10:........................................................................................................................... 60

For 1C11:........................................................................................................................... 61

For 1C12:........................................................................................................................... 62

For 1C21:........................................................................................................................... 63

For 1C25:........................................................................................................................... 64

For 1C27:........................................................................................................................... 65

For 1C28:........................................................................................................................... 66

For 1C29:........................................................................................................................... 67

APPENDIX - B .......................................................................................................................... 69

Tutorial .............................................................................................................................................69

Calculation procedure for Case 1: ...................................................................................... 69

Calculation procedure for Case 2: ...................................................................................... 77

APPENDIX - C .......................................................................................................................... 78

EXCEL FORMULAE – THE FIVE STEP ANALYSIS ...................................................................78

Step 1 ................................................................................................................................ 79

Step 2 ................................................................................................................................ 79

Step 3 ................................................................................................................................ 79

Step 4 ................................................................................................................................ 79

Step 5 ................................................................................................................................ 80



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Table of Figures

Figure 2-1 The two storey building during renovation of Ground floor in 2010 ....................... 13

Figure 2-2 Plan of Foundation ............................................................................................... 13

Figure 2-3 Plan of Ground Floor............................................................................................ 14

Figure 2-4 Plan of First Floor ................................................................................................ 14

Figure 2-5 3D/View North-East side of the RC Building ........................................................ 15

Figure 3-1 - Cross section of bell tower ................................................................................. 19

Figure 3-2 - Comparision of Push over curves of retrofitted and Un-retrofittes structures ...... 20

Figure 3-3 - Typical effect of confinement of column ............................................................. 22

Figure 3-4-types of column jacket ......................................................................................... 26

Figure 3-5-column jacket....................................................................................................... 27

Figure 3-6-types of column jacket ......................................................................................... 28

Figure 3-7-column jacket (section) ........................................................................................ 28

Figure 5-1-Formwork of First Floor with the problematic columns ......................................... 43

Figure 5-2 Brief report of column in STEREOSTATIKA ......................................................... 44

Figure 5-3 Design with the use of Excel ................................................................................ 44

Figure 5-4- new section of 1C3 ............................................................................................. 47

Figure 5-5-Showing the new section of 1C3 (plan) ................................................................ 47

Figure 5-6-Calculation and Design process for the proposed section .................................... 48

Figure 5-7-Element problem check from STEREOSTATIKA ................................................. 48

Figure 5-8-Design of jacket-section for 1C3 .......................................................................... 51

Figure 6-1-Results of Element problem check ....................................................................... 52

Figure A 1-Design of jacket-section for 1C4 .......................................................................... 56




Figure A 5-Design of jacket-section for 1C10 ........................................................................ 60







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Figure A 10-Design of jacket-section for 1C27 ...................................................................... 65



Figure A 13-Plan view of first floor ........................................................................................ 68

Figure A 14-3D view with the final sections-first floor ............................................................ 68

Figure B 1-RC Building regulation ......................................................................................... 69

Figure B 2-Specify Concrete and his properties accordance to EC 2 .................................... 70

Figure B 3-Rebar Steel and its properties in accordance to EC 3 .......................................... 70

Figure B 4-Stirrups Steel and his properties accordance to EC 3 .......................................... 71

Figure B 5-Steel section and his properties accordance to EC 3 ........................................... 71

Figure B 6-Ground type and properties ................................................................................. 72

Figure B 7-Earthquake risk zone accordance to EC 8 ........................................................... 72

Figure B 8-Stiffness Parameters ........................................................................................... 73

Figure B 9-Space Frame Parameters.................................................................................... 73

Figure B 10-Specify Units ..................................................................................................... 74

Figure B 11-Design Assumptions .......................................................................................... 74

Figure B 12-3D model of exist structure showing the element checks with colors ................. 76

Figure B 13-3D model of design structure showing the element checks with colors .............. 77



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List of tables

Table 4-1 Plot for ratio d’/h=0.05 ........................................................................................... 40




Table 4-5 Sectional areas of groups of bars (mm2)............................................................... 42

Table 4-6 Perimeter and weight of bars ................................................................................ 42

Table 4-7 Sectional areas per meter width for various bar spacings (mm2) .......................... 42



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List of Abbreviations



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Chapter 11.1 Introduction

The final year project is undertaken by every student in his final year of study, in order to

provide him with the opportunity to work on a subject which poses interest to him.

Having considered a number of different possible projects to be examined and after

having discussed the various alternatives with Professor Dr. Christou Petros, we have jointly

decided that my final year project should focus on the following matters:

the year project should be associated with the immediate present and future of the science of

Civil Engineering in the Republic of Cyprus. It is well known that Cyprus is an island and

therefore there is a limited ability to construct new buildings because the land is small. It can

be supported that it is of an immense importance to focus on alternative ways of

constructions. The alternative way which will be analyzed thoroughly in this dissertation is the

need to undertake additions to existing reinforced concrete buildings either by adding

additional floors or by expanding the said building. In order to undertake the aforementioned

actions, the static adequacy and antiseismic study of the reinforced concrete building need to

be taken into account so as to determine the type of construction which may be used and the

type of reinforcements which will be required to the various elements of construction (beams,

columns).

The main objective of this Project will be the evaluation of the capacity of an existing

RC building, the subsequent addition of an extra storey and retrofitting of structural elements

where is necessary. The choice of that is because this is the majority in Cyprus.

As part of the methodology plan to be followed the following steps will be taken:

a simulation of the current RC building will be undertaken;

the structure will be analyzed and designed via the use of a commercial software

namely STEREOSTATICA;

subject to the structural analysis to be produced the next step will be to determine the

appropriate reinforcement to be carried out so that the additional floor is added with

safety;

the addition will have to be in line with the relevant Cypriot Legislative Framework and

with the Eurocode 2, Eurocode 8; and



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subject to all of the aforementioned actions once the existing elements are evaluated

then new elements will be designed and situated accordingly.

The benefit of this Project is that in view of the impact of the economic crisis the option

of adding floors to existing buildings would in the immediate future be the preferred option

since it will be less costly than acquiring land plots and undertaking initial construction.

Therefore, via this Project it will be proved that adding floors is a viable solution and such a

solution can be in line with the Laws and Regulations of the Republic of Cyprus.

The purpose of this dissertation will be to evaluate the adequacy of the existing

building, to provide a viable solution in connection with its reinforcement (in the instance in

which the existing building is deemed inadequate) so that the addition of the extra storey is

deemed feasible and subsequently the entire building is in line and in accordance with the

European Code and especially with its provisions in connection with the antiseismic design.

This dissertation will be divided into seven chapters and three appendixes. A

summary and a short articulation regarding each of the seven chapters and the three

appendixes are provided herein below:

Chapter 1: Introduction;

Chapter 2: A short description of the existing RC building;

Chapter 3: Literature Review;

Chapter 4: The Methodology;

Chapter 5: An analysis of the results reached will be undertaken;

Chapter 6: The general conclusions reached subject to the aforementioned study will be

presented; there will be a short analysis of the advantages and disadvantages

associated with the use of STEREOSTATIKA software and other conclusions reached;

Chapter 7: A detailed list of the references relied for the purposes of this dissertation;

Appendix-A: Solutions for the rest of Columns;

Appendix-B: Tutorial of the Calculation procedure in STEREOSTATIKA;

Appendix-C: Preview of the Excel Formulae



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Chapter 2

2.1 Description of the existing building

The actual building which will be analyzed for the purposes of my final year project is an

existing two floor residential building located in Strovolos, Nicosia and was constructed in two

stages.

The ground floor was built in 1967 and the first floor was subsequently constructed

and added in 1980.

The dimensions of the ground and first floor respectively as they appear on the plan are the

following: 16900x13400 (figure 2.3) and the 16900 x11200 (figure 2.4). At the infrastructure

of the building we encounter the method of foundation beams and at the superstructure of the

building on the ground floor the majority of the sections of the columns are 350x400 and the

beams are 200x450 and in connection with the first floor the majority of the sections of the

columns are 200x300 and the beams are 200x450 and finally the depth of Slabs are 15cm.

The basic structural materials that were used were the following: Concrete C20 and Steel

S400.

In 2010 the ground-floor was renovated with the aim to extend its coverage area

(figure 2.1). Due to this extension, the majority of the existing columns had to be reinforced

with cementitious mixture Emaco T545 so as to improve wear resistance and also the section

of the columns was increased to 350x400.



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Figure 0-1 The two storey building during renovation of Ground floor in 2010

The plans of the existing building are shown below:

Figure 0-2 Plan of Foundation



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Figure 0-3 Plan of Ground Floor

Figure 0-4 Plan of First Floor



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3D/View of the existing RC Building in Figure 2.5

Figure 0-5 3D/View North-East side of the RC Building



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Chapter 33.1 Literature Review

Undoubtedly nowadays there is a wide spectrum of civil engineering structures that are being

constructed.

For example, buildings, bridges, dams, underground storage structures, overhead

storage structures, high-rise structures, launch pads, airport terminals, stadia, shopping malls,

Cineplex’s, swimming pools, etc., are some of the structures which have been built in order

to accommodate different purposes and to carry out different activities. These structures are

constructed with the use of materials such as masonry, concrete, steel and aluminum. The

material to be used is subject to the following two considerations: a) the design requirement

and b) the economic aspect.

These structures are subjected to different geophysical and man-made loads during

their service life. When the magnitude of these loads exceed the capacity or strength of these

structures, then they are likely to sustain damages. Taking into account that a) building a

new structure to replace the existing structure is an expensive option and b) that during the

construction of the new structure there will be an interruption in the use of the structure with

subsequent financial losses to the owners, as well as other economic and environmental

factors, the decision to repair and reinforce the existing "damaged" structure becomes more

imminent. Sometimes the strength of a structure is reduced because of the use of

substandard materials in its construction or due to the application of additional load because

there is a change in its functioning or due to seismic forces for which were not taken into

account in the original design of the structure.

The aforementioned situations warrant strengthening or up-gradation of the structure

so as to enable it to carry the enhanced loading. A variety of structural up-gradation and

retrofitting techniques have evolved and applied in practice over the years subject to the

potential structure in place. Some methods of seismic up-gradation such as the addition of

new structural frames or shear walls have been proven to be impractical because they have

been either too costly or their use has been limited only to certain types of structures. Other

strengthening methods such as grout injection, insertion of reinforcing steel, pre-stressing,

jacketing, and different surface treatments have been summarized by Hamid et al. (1994).

Each of these methods involves the use of skilled labour and disrupts the normal functions of

the building.



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These well-known techniques may sometimes be inadequate if the intention is to preserve

architectural heritage with added historical value. FRP composites are now increasingly used

in the construction industry and offer considerable potential for greater use in buildings,

including large primary structures. In recent years more complex applications have been

developed to satisfy the desire for more dramatic features in building design. FRP composites

have numerous potential advantages in building construction including the following: a) offsite

fabrication and modular construction reduced mass, b) superior durability c) ability to mould

complex forms, d) special surface finishes and effects, and e) improved thermal insulation

and f) lack of cold bridging (Kendall, 2007).

As a repair material Polymeric Matrix or FRP presents also significant advantages in

comparison to more traditional confinement techniques such as: a) the cross sectional

dimensions of the column do not increase and this permits compliance with architectural

restraints; b) the mass of the column does not increase, which means that the seismic

behavior of the building remains unchanged (Minicelli & Tegola, 2007); c) the low weight of

FRP materials implies that the installation procedure is faster, easier and less dangerous for

the operator than implementing traditional confining techniques. Modern techniques of

confinement consist of wrapping sheets or laminates with FRP .

During the last decade these techniques were introduced in engineering practice as

innovative confinements techniques and as an alternative to wood or steel ties which were

applied in the past. Therefore the use of FRP laminates for retrofitting and strengthening is a

valid alternative technique because of its small thickness, high strength-to- weight ratio and

ease of application.

Having reviewed the available literature on this matter, this paper presents a number

of case studies regarding the application of FRP to strengthen and retrofit masonry in un-

reinforced and reinforced structures; concrete structures; pre-stressed concrete structures;

masonry arches; underwater piles; bridge piers; monumental structures, etc.

3.1.1. Retrofitting of a medieval bell towerRetrofitting of existing structures so as to enable them to resist seismic actions which were

originally not accounted in the design is very common in structural engineering. Seismic

retrofitting of monument structure demands compliance with restrictive constraints related to

the preservation of original artistic and structural features. Any conceived intervention must

aim to attain structural performance whilst the appearance and structural mechanism of the



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original monument be respected and the intervention be as less invasive as possible. The

intervention on the bell tower of Santa Lucias Church in Serra San Quirico, Ancona, Italy is

an example of the application of composite materials for the seismic retrofit of historic

monuments where traditional retrofit strategies are not suitable. Cosenzo and Iervolino (2007)

have presented a case study which focused on the retrofitting of the medieval bell tower of

Santa Lucias Church in Serra San Quirico using the FRP.

The bell tower of Santa Lucias Church is a multilayered masonry structure which was

built in the XV century and was affected by the Umbria-Marche earthquake that took place in

1997. It is located at the centre of the little tower of Serra San Quirico, a medieval suburb

near Ancona and is surrounded by many residential constructions of the same age.

It is a calcareous masonry building; about 30 m in height and 1,200 m in width with a

rectangular plan view (Fig. 3.1). By reason of the fact that similar structures in the same area

sustained damage and those structures failed to resist to seismic loads, the local

Architectural Heritage Supervision Office expressed its desire to improve the seismic capacity

of the tower. Initially, in order to fulfill the scope of retrofitting an intervention based on steel

reticular system anchored to the inner side of the tower was proposed. The Architectural

Heritage Authority recognized that this intervention violates the above described principles

and, therefore, rejected it. Subsequently an FRP intervention was proposed, designed,

approved and installed.

The design also included a finite element simulation and a site structural assessment. The

effectiveness of the intervention was evaluated by performing nonlinear static analysis, i.e.,

push over analysis, both on retrofitted and original structures and by comparing the results.

Pushover curves for the retrofitted and un-retrofitted structures are provided in Fig 3.2.

The FRP intervention enhanced the seismic capacity of the bell tower structure and is

fully provisional as it may be removed by heating the FRP with a hot air jet.



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3.1.2. Underwater pre-stressed piles repairMullians et al. (2005) have provided a field demonstration study to evaluate the application of

FRP in connection with the underwater repair of corroding prestressed piles. A total of four

full sized 350 mm × 350 mm square pre-stressed piles were wrapped, two with carbon and

two with glass. Two of these wrapped piles, i.e., one carbon and one glass, were

instrumented to allow evaluation of their post wrap performance. Two other unwrapped piles

served as control. Instrumentation allowed determination of the corrosion potential over the

unwrapped surface and the corrosion rate for the wrapped piles.

Figure 0-1 - Cross section of bell tower



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Figure 0-2 - Comparision of Push over curves of retrofitted and Un-retrofittes structures

The study proved that the underwater wrapping in a visible system. As with most FRP

retrofits, surface preparation is of paramount importance. In this case, surface preparation

required equipment capable of operating underwater so as to grind sharp corners.

Although initial field tests on the witness panels indicated that the bond between the

wet concrete and the FRP was relatively poor, laboratory tests indicated that the bond was

adequate to restore the full undamaged capacity. Corrosion rate measurements illustrated

that the performance of the wrapped piles is consistently better than that of the unwrapped

controls. The underwater wrap used a unique water activated urethane resin system that

eliminated the need for cofferdam construction. The preliminary findings were quite

encouraging and suggested that underwater wrapping without cofferdam construction may

provide a cost-effective solution for pile repair.

3.1.3. Retrofitting of hollow bridge piersIn order to maximize efficiency in terms of the strength-to-mass and stiffness-to-mass ratios

and to reduce the mass contribution of the pier-to seismic response, it has been common

engineering practice to use hollow sections for bridge piers, particularly for tall piers. Hollow



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bridge piers are currently being used in high speed rail and highway projects in Taiwan.

Recent earthquakes such as the Northridge earthquake of 1994, the Kobe earthquake of

1995, and the Taiwan earthquake of 1999, have respectively demonstrated the vulnerability

of older reinforced concrete piers to seismic deformation demands and shear strength. Yeh

and Mo (2005), have presented the results of their research on hallow piers retrofitted with

carbon fiber reinforced polymer (CFRP) sheets.

In their research the authors have tested circular and rectangular hallow bridge piers

retrofitted by CFRP sheets under a constant axial load and a cyclic reversed horizontal load

to study their seismic behavior, including flexural ductility, dissipated energy and shear

capacity. An analytical model was also developed to predict the moment curvature

relationship of sections and the lateral load displacement relationship of piers. The test

results were also compared with the proposed analytical model. It was found that the ductility

factor of the tested piers ranged from 3.3 to 5.5 and that the proposed analytical model could

predict the lateral load displacement relationship of such piers with reasonable accuracy. All

in all, it was concluded that CFRP sheets can effectively improve the ductility factor and the

shear capacity of hollow bridge piers.

3.1.4. Strengthening of R.C. beam – column jointsRecent earthquakes that have occurred across the world have illustrated the vulnerability of

existing reinforced concrete (RC) beam-column joints to seismic loading. Strengthening of

R.C. joints is a challenging task that poses major practical difficulties.

A variety of techniques applicable to concrete elements have also been applied to

joints with the most common ones being the construction of RC or steel jackets. However,

these techniques have an inherent limitation which takes the form of intensive labour and

artful detailing. In the case of concrete solutions there is a great possibility o that the

dimensions and weights of the elements are to increase.

Recently, a new technique based on the FRP for structural elements has evolved.

This technique involves the use of FRP as externally bonded reinforcement (EBR) in critical

regions of RC elements. FRP materials which are available today in the form of strips or in

situ resin impregnated sheets, are used to strengthen a variety of RC elements, including

beams, slabs, columns, and shear walls, to enhance the flexural, shear, and axial capacity of

such elements.



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The results of a comprehensive experimental program presented by Antonopoulos

and Triantafillou (2003) focused in providing a basic understanding of the behavior of shear-

critical RC joints strengthened with FRP under simulated seismic load. The role of various

parameters such as area fraction of FRP; distribution of FRP between the beam and the

columns; axial load of column; steel reinforcement in internal joint; initial damage; carbon

versus glass fibres; sheet versus strips; and the effect of transverse beams, on the effective

FRP has been examined through 2/3 scale testing of 18 exterior RC joints.

In the aforementioned study the performance of the tests demonstrated that externally

bonded FRP reinforcement is a viable solution towards enhancing the strength, energy

dissipation, and stiffness characteristics of poorly detailed RC.

Figure 0-3 - Typical effect of confinement of column

Joints in shear that are subjected to simulated seismic loads. Relatively low fraction of

FRP area enhanced both in the peak lateral load capacity and the cumulative dissipated

energy up to about 70 to 80 percent. The increase in stiffness varied and the imposed

displacement level reached values in the order of 100 percent. The results demonstrated the

important role of mechanical anchorages in limiting premature de-bonding.



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3.1.5. Concrete confined with FRP tubesAxial load on concrete results in the lateral expansion of the concrete. In an encased

concrete column, this lateral expansion is resisted by the hoop action of the shell that

surrounds the concrete. Such confinement changes the stress-strain behavior of concrete

and also increases its compressive strength as shown in (Fig. 3.4), which depicts the typical

stress-strain relationship of un-confined concrete, confined by FRP tube and by a steel tube

respectively.

The advantage of improved performance of concrete encased in steel tubes has been well

recognized and is used in structural applications (Choi and Xiao, 2010). However, the use of

FRP tubes to encase concrete columns instead of steel is a more recent development that

offers certain advantages, such as the elimination of corrosion of the confining tube. FRP

tubes are also light-weight and easy to handle. They act as an ideal formwork that eventually

remains in place as permanent part of the structure.

The confining pressure of an FRP shell subjects the core concrete to a tri-axial state

of stress. Concrete itself prevents the shell from buckling inward. The shell protects the

concrete surface from physical damage and environmental effects such as carbonation and

chloride penetration. The shell acts as a uniform longitudinal reinforcement located at the

most advantageous position so as to resist moments. Therefore, concrete confined with FRP

is currently considered as a technically attractive system for piles, highway overhead signs,

and other compression members that can be subjected to moments. Bacque et al., (2003)

developed analytical models in order to predict the stress-strain curves for concrete confined

with FRP. Having used the analytical models, the predicted stress-strain curves for confined

concrete were compared with those that resulted by reason of the tests on concrete

specimens confined with FRP. The agreement was found to be good.

The proposed model was also able to predict that concrete confined with a GFRP

exhibits better ductility as compared with concrete confined with CFRP. The above is a very

well-known and expected behavior of concrete confined with GFRP.

3.1.6. Heritage university buildingNanda and Sahoo (2010) have presented the factors that were influencing the damages and

the repairing methodology to be adopted in connection with the restoration work of the

heritage Ravens Haw University situated on Orissa and originally constructed in 1868. Fine

cracks in the walls were sealed with epoxy putty instead of wall stitching. Four grouting port



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holes were provided along the cracks. Nozzles were fixed and grouting was performed with

water-insensitive high-bond strength epoxy of density 1.1 kg/L, compressive strength 75 MPa,

tensile strength 34 MPa, and bond strength 3.5 MPa. Styrene Butadiene rubber emulsion

based latex modified concrete was used to apply a ferrocement treatment so as to repair the

leaking roof of the building.

3.1.7. Arresting leakage in Muran damThe step by step approach in "arresting" water leakage that was taking place in the inspection

gallery of Muran Dam via the use of Polyurethane (PU) injection system was described by

Mishra (2010). The Muran Dam is located on Muran River in Khatiguda in Orissa. The walls

of the inspection gallery were made out of concrete and were constructed in an old pattern.

Keeping in mind the age, the thickness, the strength and other physical conditions, a PU

injection system was considered for arresting leakages. Following the elapse of a

considerable time as of the repair, the engineer in-charge confirmed that the system was

completely successful as the affected area was intact even after the rise of the water levels in

the upstream side.

3.1.8. Reinforced Concrete jacketingIf possible, a four sided jacket should be used. For its design, a monolithic behavior of the

composite columns can be assumed. The minimum width of the jacket should be 10 cm for

concrete cast in place and 4 cm for concrete. Two main types of column jacketing have been

used, as shown in figure 3.4. The type illustrated in figure 3.4a is used to increase the shear

capacity of the column and thus it aims to accomplish a strong column- weak beam design.

The second type, where the longitudinal steel of the jacket is made continuous through the

slab system and is carefully anchored to the foundation, was widely used in Cyprus,

simultaneously with the jacketing of the beams, (reference is made in figure 3.4b). Because

of the existence of the beams, usually the longitudinal reinforcement was concentrated in the

column comers, where bar bundles were used. It is recommended that no more than 3 bars

are bundled together. Windows are usually bored through the slab to allow the steel to go

through, as well as to enable the concrete casting process.

Figures 3.5b and 3.5c show options for the detailing of the longitudinal reinforcement

to avoid the excessive use of bundles.



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The percentage of steel with respect to the jacket area should be limited in the range

between 0.015 to 0.04, and at least a #5 bar should be used at every corner for a four

sided jacket.

Shear reinforcement should be designed and spaced subject to earthquake design

practice, although it is suggested that the minimum bar diameter used for ties is no less than

9.5 mm (#3 bar) or 1/3 the diameter of the biggest longitudinal bar. The ties should have 135°

hooks with 10 bar diameters of anchorage. In Cyprus, due to

the difficulty of manufacturing 135° hooks on the field, 90°

hooks were provided to the ties of several structures. To avoid

this problem, ties made of multiple pieces, as shown in figure

2.5, can be used.

Another aspect that has been observed in Cyprus is

the significant change encountered in connection with the

shear span/depth (a/d) ratio of existing columns once they are

jacketed. In several jacketing schemes used in framed

buildings in Cyprus, where the typical story height is 3 m, columns’ a/d ratio (computed

assuming an inflection point exists along the height of the member) would be typically

reduced to values less than two and in some cases to ratios less than 1.5. A column with this

a/d ratio is very likely to change from a flexural behavior to a shear dominated one. This type

of column, which is subjected to a double curvature deformation, would behave very similar to

a deep beam coupling two shear walls: shearing forces and consequent diagonal cracking is

likely to cause radical redistribution of tensile forces along the flexural reinforcement. Due to

the effects of diagonal tension, members with a/d ratios less than about two have tensile

stresses acting along the entire length of their longitudinal reinforcement, even at locations

where conventional flexural theory would predict compressive-stresses. This was observed

by Paulay (1971) in deep beams, and by Bett, et.al. (1985) in jacketed short columns.

For a column with continuous longitudinal steel (figure 2.6b) the conventional design

guidelines for flexural concrete elements could be potentially invalidated, because both

tension and compression steel could be in tension at a critical section. Thus, the interaction of

flexure and shear in this type of elements causes a reduction in the flexural capacity. The

inelastic behavior of such members is likely to be strongly affected by shear effects and thus

their energy dissipation capacity will be diminished.

The lack of space in the structure makes it very difficult to provide midface



26 | P a g e

longitudinal bars, as shown in figure 3.7, or supplementary crossties to confine the concrete

on this portion of the column. Bett, etal.(1985) concluded that although this supplementary

longitudinal and transverse reinforcement did not have a significant effect on the monotonic

stiffness and strength of jacketed short columns for small drifts, they were beneficial in

controlling the strength and stiffness degradation under repeated cycles of reversed

displacements exceeding 2% drift, where the column worked within its inelastic range of

behavior.

Although it cannot be asserted that a jacketed column would have a double curvature

deformation during an earthquake, the above discussion has shown that its design is not an

easy task and its behavior is uncertain. One aspect that should be outlined is that deep

concrete elements are not likely to behave adequately in the inelastic range when they are

not detailed properly (this is the case for the majority of jacketed columns in real structures).

This points to the fact that when a framed structure is jacketed, energy dissipation should be

concentrated at the beams, while the columns should remain elastic or have limited inelastic

demands. Even in the instances where the a/d ratio is not reduced to values observed in

Mexican practice, the impossibility to provide adequate detailing for inelastic behavior of the

jacketed columns leads to a strong column-weak beam design.

Figure 0-4-types of column jacket

(a) (b) (c)



27 | P a g e

Figure 0-5-column jacket



28 | P a g e

Figure 0-6-types of column jacket

1. additional reinforcement2. existing reinforcement3. additional ties4. existing rc concrete5. additional rc concrete6. dowels

1

3

4

6

2

5

Figure 0-7-column jacket (section)



29 | P a g e

3.1.9. Examples of repairing structural elements with the use ofjacketing:



30 | P a g e



31 | P a g e



32 | P a g e



33 | P a g e



34 | P a g e



35 | P a g e



36 | P a g e



37 | P a g e

The use of FRP as a strengthening and retrofitting material has several advantages over the

use conventional materials in such a way. Its thickness is small and hence its application

does not add weight to existing structures. It helps to preserve the cultural heritage of

monumental structures. It is not corrodible. In the case study of the bell tower of Santa

Lucias Church in Serra San Quirico, Ancona, Italy it was shown that the FRP intervention

enhanced its seismic capacity and such a solution was acceptable to the local Architectural

Heritage Authorities.

Underwater FRP wrappings without cofferdam construction could provide a cost

effective solution for pile repair. CFRP sheets can effectively improve the ductility factor and

the shear capacity of hollow bridge piers. It was found that the ductility factor of tested piers

ranged from 3.3 to 5.5. It has been demonstrated via the application of experiments that

externally bonded FRP reinforcement is a viable solution towards enhancing the strength,

energy absorption and stiffness characteristics of poorly detailed RC joints in shear.

The use of FRP tubes to encase concrete columns instead of steel is a more recent

development that offers certain advantages, such as the elimination of corrosion of the

confining tube. FRP tubes are also light-weighted and easy to handle. The heritage university

building was restored by repairing the fine cracks of the walls by epoxy injection and via the

use of ferrocement treatment using latex modified concrete to repair the leaking roof. The

leakage in the walls of the inspection gallery in a dam was arrested by Polyurethane (PU)

injection system.

3.1.10. Decision of retrofit methodHaving reviewed the two types of reinforcement available and namely on the one hand the

FRP reinforcement and on the other hand the reinforced concrete jacketing, I have reached

to the prima facie conclusion that the method of FRP should not be opted for subject to the

following considerations:

the designing process would have been extremely difficult;

there is no sufficient background and expertise in the use of this method in Cyprus; and

the cost would have been detrimental.

Therefore I have decided to apply the method of reinforced concrete jacketing for the

purposes of this dissertation subject to the following two principal considerations:

it’s been widely and customarily used; and

there is sufficient background knowledge and expertise in its use in similar occasions.



38 | P a g e

Chapter 44.1 Methodology

The steps that I undertook can be enumerated and listed as follows:

1.1.1. Initially I found the drawings relating to the existing RC building;

1.1.2. I went on location and I compared the building in connection to the drawings I had in

my possession;

1.1.3. The next step was to design the model of the exististing RC building with the

assistance of the commercial software STEREOSTATIKA;

1.1.4. Following, I added an additional floor and I did run the software with different load

combinations of Earthquake in accordance to Eurocode 8. Different results were

produced and I made use of the results (N ,M ) relating the worst load

combination for each problematic column;

1.1.5. Having in mind the following factors:

the existing condition of the building and

that the method of column reinforcement would be the jacketing method it was

evident that part of the capacity of the existing column would have been used for

the calculations for the design of the new reinforcement section.

As a result of all of the above, the following decisions were taken:

Regarding the existing section:

o safety factor 10% for the strength Grade of the reinforced concrete

( 20 18)

o safety factor 10% for the strength Grade of steel ( 400 360)

o safety factor 30% for the capacity of steel reinforcement

Regarding the proposed section:

o safety factor 10% for the strength Grade of reinforced concrete

( 30 27)

o safety factor 10% for the strength Grade of steel ( 500 450)

o New dimensions of the section from 200 300 to 400 300

1.1.6. The next step concerned the use of Excel (refer to APPENDIX-C). In the said

software I applied the results of STEREOSTATIKA (N ,M - see figure 5.2) in



39 | P a g e

combination with the aforementioned parameters and I made use of the end results

regarding the proposed steel reinforcement ( ) of the new section.

1.1.7. I went back to STEREOSTATIKA, and I applied the new data (A , handb) and I

rerun it and I observed that the problematic was no longer problematic and the said

column no longer encountered a capacity problem. Therefore, subject to the above I

proceeded with producing the final design of the proposed section.

1.1.8. The final step concerned the repetition of the aforementioned procedure for all the

problematic columns (refer to APPENDIX- A)



40 | P a g e

Tables and charts that I used for the calculations:

Table 0-1 Plot for ratio d’/h=0.05




41 | P a g e





42 | P a g e

Table 0-5 Sectional areas of groups of bars (mm2)

Table 0-6 Perimeter and weight of bars

Table 0-7 Sectional areas per meter width for various bar spacings (mm2)



43 | P a g e

Chapter 55.1 Analysis and Results

As it was expected, in the course of the antiseismic analysis, the following columns in the first

floor had a capacity problem (figure 4.1):1C3, 1C4, 1C5, 1C6, 1C7, 1C10, 1C11, 1C12, 1C21, 1C25, 1C27, 1C28, 1C29

Figure 0-1-Formwork of First Floor with the problematic columns

Herein below, there will be an analysis of the procedure followed in connection with the

design and the reinforcement method applied in connection with column 1C3. The remaining

solutions (design and reinforcement) of all other problematic columns will be presented in

Appendix A of this dissertation.

5.1.1. Data collectionInitially by adding the extra storey, I will make use of the following elements N ,M

which will result in STEREOSTATICA (figure 4.2), by way of the least beneficial load



44 | P a g e

combination of each column. It has to be noted that STEREOSTATIKA included all necessary

parameters in accordance with Eurocodes' 2, 3 and 8.

For column 1C3:

Figure 0-2 Brief report of column in STEREOSTATIKA

5.1.2. Procedure - Evaluation of DataThe data were evaluated manually via the use of Excel (figure 5.3) with a factor of safety in

the region of 10% in connection with the existing grade of RC concrete and grade of steel.

The reasoning behind this approach was due to the fact that I was unaware of the existing

condition of the column. In addition, I will also cross check if the columns are sufficient in

connection with their reinforcements and I will simultaneously cross check the results of

STEREOSTATIKA.

Figure 0-3 Design with the use of Excel



45 | P a g e

Bending check:

30 , 6

Loadcombination: 4B(thiswastheleastbeneficialloadcombinationinaccordancetoSTEREOSTATIKA)

Reactions

119.9 KN

11.9 KNm

28.7 KNm

Data

h (mm) b (mm) Cover (mm) Link (mm) R/C bar (mm) Fyk Fck

300 200 30 6 14 360 18

= + +12 = 43

= 257

= = 157

= 46

<

= 183

= + = 54

.

= + = 35

= 1 = 0.89(0.3 < < 1.0)



46 | P a g e

= 35

4 :

=0.14 0.15

= 0.11

= 0.25 => =

= 0.11

In connection with the existing column 1C3: 200 300mm, the reinforcement is only

< and therefore my conclusion is that it needs to be reinforced.

5.1.3. Output - ResultsThe next step is to turn again to STEREOSTATIKA but in this occasion the dimensions of the

section will be altered from 300 200mm to 400 300mm and the program will be evaluated

again subject to the new input parameters.

Following the above, I will take the new results N ,M which have already

taken into account the least beneficial load combination of each column subject to

STEREOSTATIKA.

The below figures 5-4 and 5-5 are showing the new section for column 3



47 | P a g e

Figure 0-4- new section of 1C3

Figure 0-5-Showing the new section of 1C3 (plan)



48 | P a g e

At figures 5.6 and 5.7 in below you can see the process of calculations with the use of

STEREOSTATIKA

Figure 0-6-Calculation and Design process for the proposed section

Figure 0-7-Element problem check from STEREOSTATIKA

It has been observed that by increasing the dimension of the section of 1C3, this leades to

positive results and the set column no longer encounters adequacy problems (reference to

figure 5.7).

1C3



49 | P a g e

To conclude I will repeat the procedure via the use of the manual method in Excel for the

same column (1C3). However, the difference being that the dimension of the section has

now been increased to 400 300mm as well as the grade of concrete has been altered from

C25 to C30/37 (factored) and the grade of steel has been altered from S400 to B500

(factored). In addition, I will not take into account the existing reinforcement in the range of 30%

and I will make use of the remaining 70% in connection with the new dimensions of the

problematic columns and in that way I will reach to the final design of the dimensions of the

columns which will be performed via the jacketing method.

For Column 1C3

Bending check:

Loadcombination: 2C

Reactions

99.9KN

71.8KNm

93.1KNm

Data

h (mm) b (mm) Cover (mm) Link (mm) R/C bar (mm) Fyk Fck

400 300 30 10 14 450 27

= + +12 = 47

=

= =

= 203

<

= 368



50 | P a g e

= + = 198

.

= + = 143

= 1 = 0.97(0.3 < < 1.0)

= 143

8 :

=0.12 0.15

= 0.03

= 0.25 => =

= 0.11

70% 4 14 + 8 18 430 + 2036



51 | P a g e

5.1.4. Final Results:

For Column 1C3

Herein below (figure 5.8) you can see the proposed section which is result from thecalculations.

Proposed Section of 1C3:

Figure 0-8-Design of jacket-section for 1C3



52 | P a g e

Chapter 66.1 Discussion

The results that have been reached can be characterized as positive and impressive since in

certain occasions (for instance in figure 6.1) column 1C3 following the increase of its

dimension no longer encountered a capacity problem. In addition, it was observed that by

increasing the dimension of 1C3, columns IC7 and IC25 were relieved from the extra load

that was affecting them.

As the owner of the building, this result was extremely encouraging since it could

mean that by combing strategically a combination of particular columns which would have

relieved the problematic columns from the extra burden I would have incurred an economic

advantage since a considerable amount would have not have been spend in reinforcing all

the columns.

However, by being professional and with the aim of ensuring the absolute safety and

durability of the structure, I have decided that the safest approach is to proceed with the

reinforcement of all columns respectively irrespective of the results deduced via the use of

STEREOSTATIKA (see figure 6.1).

Figure 0-1-Results of Element problem check

1C7

1C3 1C25



53 | P a g e

6.1.1. General ConclusionsFirst and foremost the biggest disadvantage of STEREOSTATIKA is that it cannot analyze

and design the dimension of a column via the jacketing method. Nowadays concrete grade

C20/25 is no longer being used for columns and instead concrete grade C30/37 is being used.

Therefore, in connection with my own calculations I had to proceed with a percentage of 10%

C30 C28 and the same was affected with respect to steel grade (10% B500 B450).

STEREOSTATIKA does not provide the option of calculating a dimension in connection with

the inner part of an existing column with a concrete grade C20/25 and with steel grade S400

and with concrete grade C30/37 and steel grade B500 in the perimeter of the existing

dimension.

In addition, another important problem associated with the use of STEREOSTATIKA

is that the grade for concrete and steel are predetermined in the set software and therefore

you are not allowed to insert your own evaluation. For instance, you are precluded to

evaluate that a column which is in the category of grade C30 is instead in the category of

grade C28. In certain occasions, such evaluation might be necessary in order to

accommodate the risk that the given building is an old construction and hence such an

evaluation is necessary for safety reasons. Therefore, you are forced to undertake the

aforementioned action manually or via the use of different software. The same is applicable

with respect to steel. Personally, I decided that with respect to the new dimension the

beneficial capacity of the existing reinforcement is limited to the range of 70%.

Despite the aforementioned disadvantages associated with the use of

STEREOSTATICA, the set software has certain advantages. For instance the 3D graphs'

are simple in their use. I was also enabled in a rather simple and fast track way to alter the

parameters of the dimensions of the columns, to reach to solutions and to repeat the same

procedure numerous times so as to ensure the best possible result.

Following the review of an extensive bibliographical study and several design projects

in connection with the retrofit of structures, it can be concluded that there are some outlines

that are helpful, not only in a qualitative but in a quantitative manner, the design of a retrofit

scheme of a structure by means of concrete jacketing.

Although these guidelines can constitute a rational basis for a practical design,

further research needs to be undertaken so as to address certain critical aspects in the

behavior of jacketed elements. The change encountered in the behavior of jacketed

elements, whose shear span/depth ratios are significantly reduced due to their jacketing



54 | P a g e

needs to be further clarified. The conventional design guidelines related to flexural concrete

elements can provide un-conservative results when they are applied to the design of such

members. Experimental research needs to further address this issue, including without

limitation the further study of biaxial bending effects on the behavior of wide columns.

To conclude, the procedure of reinforcing the columns by reinforced concrete must

take place once there is a full knowledge and understanding of the extend of the problem. In

parallel, it is absolutely necessary to ensure that the works to be performed are being

thoroughly supervised. The problems related to the actual construction and the experience of

the civil engineer entrusted with the role of supervision will determine whether the

reinforcement will be effected in an economic and efficient way. It is noteworthy to provide the

undisputed fact that the cost associated with the reinforcement is on numerous occasions

greater than the cost related to the initiation of a "new" construction due to the fact that the

reinforcement is interconnected with demolition, welds, grout and an inability to use

mechanical means.



55 | P a g e

Chapter 7References

1. Antonopoulos, CP and Triantafillou, TC (2003) Experimental Investigation of FRP-

Strengthened R.C. Beam-Column Joints. J. Composites and Construction, ASCE, 7(1),

pp. 39.

2. Bacque, J Patnaik, AK and Rizkalla, SH (2003) Analytical Models for Concrete

Confined with FRP Tubes. J. Composites and Construction, ASCE, 7(1), pp. 31-38.

3. Choi, KK and Xiao, Y (2010) Analytical Studies of Concrete-Filled Circular Steel Tubes

under Axial Compression. J. Structural Engineering, ASCE, 136(5), pp. 565-578.

4. Cosenzo, E and Ivervolino, I (2007) Case Study Seismic Retrofitting of a Medieval Bell

Tower with FRP,” Journal of Composites for Construction, ASCE, 11(3), pp. 319-327.

5. Hamid. AA Mohmond, ADS and El Magal, SA (1994) Strengthening and Repair of Un-

reinforced Masonry Structures: State-of-the-art, Proceedings of the 10th International

Brick and Block Masonry Conference, Vol. 2, Elsevier Applied Science, London, pp.

485-497.

6. Kendall, D (2007) Building the Future with FRP Composites.Reinforced Plastics, May,

pp. 26-33.

7. Minicelli, F and Tegola, LA (2007), Strengthening Masonry Columns: Steel Strands

Versus FRP, Proceedings of the Institution of Civil Engineers Construction Materials Vol.

160, Issue CM2, May, pp. 47-55.

8. Mishra, A (2010) Arresting Leakges on the Inside Walls of Inspection Gallery (Muran

Dam) of Upper Indravathi Hydro Electric Project, Orissa, India – A Case Study, Int. J 3

R’s, (1)2, pp. 87 – 89.

9. Mullians, G Sen, R Suh, K and Winters, D (2005) Underwater Failure-Reinforced

Polymers Repair of Prestressed Piles in the Allen Creek Bridges, J. Composites and

Construction, ASCE, 9(2), pp.136-146.

10. Nanda, R and Sahoo, DK (2010) Restoration of a Heritage University Building – A Case

Study, Int. J.of 3 R’s, 1(2), pp. 84 – 86.

11. Yeh, YK and Mo YL (2005) Shear Retrofit of Hollow Bridge Piers with Carbon Fibers-

Reinforced Polymers Sheets, J. Composites and Construction, ASCE, 9(4), pp.327-336.



56 | P a g e

APPENDIX - ASolutions for the rest of Columns

For 1C4:FOR COLUMN: 1C4PROPOSED As (mm2) : 1440

EXIST CONDITION h

(mm)

b

(mm)

Cover

(mm)

Fyk

S.F

10%

Fck

S.F

10%

Link

(mm)

R/C

bar

As(mm2)

S.F30%

300 200 30 400 20 6 4Y14 616

PROVIDE (JACK) h

(mm)

b

(mm)

Cover

(mm)

Fyk

S.F

10%

Fck

S.F

10%

Link

(mm)

R/C

bar

A's(mm2)

400 300 30 500 30 10 8Y14 1232

1663 mm2

Figure A 1-Design of jacket-section for 1C4



57 | P a g e

For 1C5:

FOR COLUMN: 1C5PROPOSED As (mm2) : 1080

EXIST CONDITION h

(mm)

b

(mm)

Cover

(mm)

Fyk

S.F

10%

Fck

S.F

10%

Link

(mm)

R/C

bar

As(mm2)

S.F30%

300 200 30 400 20 6 4Y14 616

PROVIDE (JACK) h

(mm)

b

(mm)

Cover

(mm)

Fyk

S.F

10%

Fck

S.F

10%

Link

(mm)

R/C

bar

A's(mm2)

400 300 30 500 30 10 8Y14 1232

1663 mm2




58 | P a g e

For 1C6:


EXIST CONDITION h

(mm)

b

(mm)

Cover

(mm)

Fyk

S.F

10%

Fck

S.F

10%

Link

(mm)

R/C

bar

As(mm2)

S.F30%

300 200 30 400 20 6 4Y14 616

PROVIDE (JACK) h

(mm)

b

(mm)

Cover

(mm)

Fyk

S.F

10%

Fck

S.F

10%

Link

(mm)

R/C

bar

A's(mm2)

400 300 30 500 30 10 8Y14 1232

1663 mm2




59 | P a g e

For 1C7:


EXIST CONDITION h

(mm)

b

(mm)

Cover

(mm)

Fyk

S.F

10%

Fck

S.F

10%

Link

(mm)

R/C

bar

As(mm2)

S.F30%

300 200 30 400 20 6 4Y14 616

PROVIDE (JACK) h

(mm)

b

(mm)

Cover

(mm)

Fyk

S.F

10%

Fck

S.F

10%

Link

(mm)

R/C

bar

A's(mm2)

400 300 30 500 30 10 8Y14 1232

1663 mm2




60 | P a g e

For 1C10:


EXIST CONDITION h

(mm)

b

(mm)

Cover

(mm)

Fyk

S.F

10%

Fck

S.F

10%

Link

(mm)

R/C

bar

As(mm2)

S.F30%

300 200 30 400 20 6 4Y14 616

PROVIDE (JACK) h

(mm)

b

(mm)

Cover

(mm)

Fyk

S.F

10%

Fck

S.F

10%

Link

(mm)

R/C

bar

A's(mm2)

400 300 30 500 30 10 8Y14 1232

1663 mm2




61 | P a g e

For 1C11:


EXIST CONDITION h

(mm)

b

(mm)

Cover

(mm)

Fyk

S.F

10%

Fck

S.F

10%

Link

(mm)

R/C

bar

As(mm2)

S.F30%

300 200 30 400 20 6 4Y14 616

PROVIDE (JACK) h

(mm)

b

(mm)

Cover

(mm)

Fyk

S.F

10%

Fck

S.F

10%

Link

(mm)

R/C

bar

A's(mm2)

400 300 30 500 30 10 8Y14 1232

1663 mm2




62 | P a g e

For 1C12:


EXIST CONDITION h

(mm)

b

(mm)

Cover

(mm)

Fyk

S.F

10%

Fck

S.F

10%

Link

(mm)

R/C

bar

As(mm2)

S.F30%

300 200 30 400 20 6 4Y14 616

PROVIDE (JACK) h

(mm)

b

(mm)

Cover

(mm)

Fyk

S.F

10%

Fck

S.F

10%

Link

(mm)

R/C

bar

A's(mm2)

400 300 30 500 30 10 8Y14 1232

1663 mm2




63 | P a g e

For 1C21:


EXIST CONDITION h

(mm)

b

(mm)

Cover

(mm)

Fyk

S.F

10%

Fck

S.F

10%

Link

(mm)

R/C

bar

As(mm2)

S.F30%

300 200 30 400 20 6 4Y14 616

PROVIDE (JACK) h

(mm)

b

(mm)

Cover

(mm)

Fyk

S.F

10%

Fck

S.F

10%

Link

(mm)

R/C

bar

A's(mm2)

400 300 30 500 30 10 8Y14 1232

1663 mm2




64 | P a g e

For 1C25:


EXIST CONDITION h

(mm)

b

(mm)

Cover

(mm)

Fyk

S.F

10%

Fck

S.F

10%

Link

(mm)

R/C

bar

As(mm2)

S.F30%

300 200 30 400 20 6 4Y14 616

PROVIDE (JACK) h

(mm)

b

(mm)

Cover

(mm)

Fyk

S.F

10%

Fck

S.F

10%

Link

(mm)

R/C

bar

A's(mm2)

400 300 30 500 30 10 8Y14 1232

1663 mm2




65 | P a g e

For 1C27:


EXIST CONDITION h

(mm)

b

(mm)

Cover

(mm)

Fyk

S.F

10%

Fck

S.F

10%

Link

(mm)

R/C

bar

As(mm2)

S.F30%

300 200 30 400 20 6 4Y14 616

PROVIDE (JACK) h

(mm)

b

(mm)

Cover

(mm)

Fyk

S.F

10%

Fck

S.F

10%

Link

(mm)

R/C

bar

A's(mm2)

400 300 30 500 30 10 8Y14 1232

1663 mm2




66 | P a g e

For 1C28:


EXIST CONDITION h

(mm)

b

(mm)

Cover

(mm)

Fyk

S.F

10%

Fck

S.F

10%

Link

(mm)

R/C

bar

As(mm2)

S.F30%

300 200 30 400 20 6 4Y14 616

PROVIDE (JACK) h

(mm)

b

(mm)

Cover

(mm)

Fyk

S.F

10%

Fck

S.F

10%

Link

(mm)

R/C

bar

A's(mm2)

400 300 30 500 30 10 8Y14 1232

1663 mm2




67 | P a g e

For 1C29:


EXIST CONDITION h

(mm)

b

(mm)

Cover

(mm)

Fyk

S.F

10%

Fck

S.F

10%

Link

(mm)

R/C

bar

As(mm2)

S.F30%

300 200 30 400 20 6 4Y14 616

PROVIDE (JACK) h

(mm)

b

(mm)

Cover

(mm)

Fyk

S.F

10%

Fck

S.F

10%

Link

(mm)

R/C

bar

A's(mm2)

400 300 30 500 30 10 8Y14 1232

1663 mm2




68 | P a g e

The plan view of first floor with the final sections in below:

Figure A 13-Plan view of first floor

Figure A 14-3D view with the final sections-first floor



69 | P a g e

APPENDIX - BTutorial

The adequacy of the building components of the existing RC building

Calculation procedure for Case 1:

Input Data to STEREOSTATIKA

Input all of the parameters in accordance with the existing condition of the RC building;

Building regulation:

Figure B 1-RC Building regulation



70 | P a g e

Specify Materials - Concrete and its properties in accordance to EC 2:

Figure B 2-Specify Concrete and his properties accordance to EC 2

Specify Materials - Rebar Steel and his properties accordance to EC 3:

Figure B 3-Rebar Steel and its properties in accordance to EC 3



71 | P a g e

Specify Materials - Stirrups Steel and his properties accordance to EC 3:

Figure B 4-Stirrups Steel and his properties accordance to EC 3

Specify Materials - Steel section and his properties accordance to EC 3:

Figure B 5-Steel section and his properties accordance to EC 3



72 | P a g e

Specify Ground type and properties:

Figure B 6-Ground type and properties

Specify Earthquake risk zone accordance to EC 8:

Figure B 7-Earthquake risk zone accordance to EC 8



73 | P a g e

Specify Stiffness Parameters:

Figure B 8-Stiffness Parameters

Specify Space Frame Parameters:

Figure B 9-Space Frame Parameters



74 | P a g e

Specify Units:

Figure B 10-Specify Units

Import the data for Design Analysis:

Figure B 11-Design Assumptions



75 | P a g e

the user can choose the solver button and subsequently Static and Dynamic analysis of the

model is performed, taking into account the calculation parameters set. The solver utilizes

the Complete Quadratic Combination (CQC) modal combination method. From the central

screen of the program, choosing Parameters > Space Frame Parameters (NTUA) the user

can select the solution method (CQC of seismic forces or CQC of Seismic Forces on MC + 4

Ecc).

During the dynamic analysis, the program performs all calculations and determines

the number of modes needed and all other design data (Eigen values, member loads, load

combinations, member deformations, reinforcement mm2 demands in every section of the

model etc) which is important for the correct estimation of the building’s response.

Then after all the necessary data are calculated, the reinforcement area demand (As,cal) for

each structural element is determined. This is an automated procedure and no user

intervention is needed.

Then all necessary data for further processing the project are created, namely all construction

drawings (formwork and reinforcement drawings) based on the reinforcement calculated on

the previous step.

After the conclusion of all calculations, element design, estimations and generation of

detailing construction drawings, the user is advised to continue to Element Problems Checkand Reinforcement Edit.



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As you can see the results for the Case 1:

Problem report

Summary of element checks:

Elements with problems: 0

Figure B 12-3D model of exist structure showing the element checks with colors

In view of the fact that none of the elements encounters problems, I proceed with the

discussion of Case 2 which relates to the addition of an extra storey.



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Calculation procedure for Case 2:

Input new data to STEREOSTATIKA and apply the same procedure provided in connection

with Case 1;

The results in connection with Case 2 are as follows:

Problem reportSummary of element checks:Elements with problems: 13

Figure B 13-3D model of design structure showing the element checks with colors



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APPENDIX - C

EXCEL FORMULAE – THE FIVE STEP ANALYSIS



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Short description of how each Step works so that other users can make use of these formulas.

Step 1With respect to step 1 you proceed to input the data (Nd, Mxd, Myd)

Step 2In terms of step 2 there 3 subcategories:

a) First in subcategory (a) you input the safety factor for the existing section and for the

proposed section to be designed (note the s.f. values will be subject to your own

evaluation).

b) Second in subcategory (b) you input the characteristic compressive strength of

concrete and the characteristic yield strength of reinforcement both in respect of the

existing section and proposed section.

c) Thirdly with respect to subcategory (c) you input the data with respect to:

1) Dimensions of the section

2) The cover

3) The links diameter

4) R/C bar diameter

Step 3With respect to step 3 automatically the calculations are undertaken.

Step 4In connection with step 4 we take the last three results and we apply them to the relevant

tables and as a result we get a particular value which we input to step 4 and it will result to

the final cross sectional area of reinforcement.



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Step 5With respect to the last step as you can establish there two columns.

a) With respect to the first column:

i. you input the safety factor for the existing steel reinforcement (note the s.f. values

will be subject to your own evaluation),

ii. the number of the existing steel-bars and their diameter

b) In terms of the second column you input the number of the proposed steel-bars to be

designed and their diameter.

Again automatic calculations will be undertaken and the program itself will verify whether the

proposed cross sectional area of reinforcement have adequate capacity.

final year project

Documents

storey structure

future perspective

existing building

retrofit of existing

static equilibrium

project report

requisite moral support

g e table of contents