Masonry Building Strengthening in StatiCAD Program
Types of Empowerment that can be made
1-Reinforcement with shotcrete
2-Reinforcement by adding vertical beam to the system
3-Reinforcement with fibrous polymer wrap
4-Strengthening by adding new walls to the system
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R,D,I coefficients for masonry buildings should be taken according to Chapter 11. However, the program applies the value given by the user.
It is necessary to calculate the DD-2 earthquake ground motion level and to achieve the controlled damage performance target. For school-type buildings, it is appropriate to take the building importance factor of 1.5.
It is appropriate to take 1 as the wall security numbers are the existing structure.
The collection of information from the building is as follows in accordance with TBDY2018.
15.2.10. Limited Knowledge Level in Masonry Buildings
15.2.10.1 – Building Geometry: If there are architectural projects, the compatibility of the existing geometry with the project will be determined by the visual inspection to be made in the building. If there is no architectural project, the system relay of the building will be obtained. The information obtained should include the location of the masonry walls at each floor, their length, thickness, spacing and floor heights.
15.2.10.2 – Details: The type of roof and flooring, the way of connection with the walls, the condition of beams and lintels will be determined visually.
15.2.10.3 – Material Properties: The type of wall materials, a part of the wall surface
plaster will be removed and detected visually. The wall shear strengths given for each wall type in Chapter 11 shall be taken as basis in the building strength calculations.
15.2.11. Comprehensive Level of Knowledge in Masonry Buildings
15.2.11.1 – Building Geometry: System relay of the building will be drawn. The information obtained should include the location of the masonry walls at each floor, their length, thickness, spacing and floor heights. The foundation system will be determined by an inspection pit to be opened from the outside of the building.
15.2.11.2 – Details: The type of roof and flooring, the way they are connected to the walls, the condition of beams and lintels will be visually examined. As a result of this examination, it will be determined whether the rigid diaphragm feature is provided at each floor. If this feature cannot be provided, it will be decided that the building is insufficient in terms of earthquake safety.
15.2.11.3 - Material Properties: The type of wall materials, a part of the wall surface
plaster will be removed and detected visually. In order to determine the wall material properties, at least two wall piece samples will be taken from the building and the average properties obtained from the compressive strength tests of these samples will be used in the calculations to be made according to Chapter 11.
The wall shear strengths given for each wall type in Chapter 11 shall be taken as basis in the building strength calculations.
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1-Reinforcement with Shotcrete
1.1 Steel mesh is placed on one or both sides of the wall in the calculated grade. In order for the steel mesh to work with the wall, it is anchored to the existing wall. The wall is covered with shotcrete or repair mortar at the calculated thickness, which gives the project strength.
In order to consider retrofitting in StatiCAD calculations, TBDY2018 regulation must be selected on the regulation selection page in the project general settings and the This project is Existing Building Inspection and Reinforcement Project option should be selected. If the RYTEIE 2019 (Risky Building) regulation is selected or the This project is an Existing Building Inspection and Reinforcement Project option is not selected, retrofitting will not be considered.
1.,2 in Project General Settings>Reinforcement Tab. and4. Options are selected
1. Buffing is ignored if option is not selected
Option 2 ensures that the contribution to the pressure capacity of the reinforcement is taken into account. If the compressive strength is sufficient on the walls, it may not be marked.
In the strengthening applied to the 1st option wall, the calculation is made with the assumption that the increase in the shear capacity of the wall is only with the shear strength of the shotcrete, and the reinforcement is placed constructively. It is not recommended because it is extremely safe and uneconomical, but it can be applied at the discretion of the engineer.
When the 2nd option is selected, the shear strength of the shotcrete is not calculated, only the shear strength of the steel mesh reinforcement is taken into account. In our opinion, it is an economical and safe solution. In this option, the additional shear strength provided by the mesh reinforcement (to prevent brittle fracture) is limited to 0.22*fcd*Amanto. If the shear strength of the reinforced wall is still not sufficient, increasing the shotcrete class or the jacket thickness according to the formula may be a solution in order to obtain sufficient performance from the reinforcement.
Since the mantle name is given automatically by the program in the incoming form, it does not need to be changed. The wall thickness value to be jacketed is entered in cm. The wall and jacket eccentricity value is maintained as zero. The length of the Manto left/bottom protrusion determines how many cm it will be extended from the clicked point to the left or the bottom, and the length of the Manto right/top protrusion determines how many cm it will be extended from the clicked point to the right or top. The concrete jacket thickness value is entered. If it is not a stepped structure or if the lower and upper level values on the walls are zero, the lower and upper levels of the concrete jacket should be left as zero.
If the top or left side of the wall will be covered, the radio Top/left side overlay button will be selected, if the right or bottom side will be covered, the Bottom right side radio button will be selected.
In case the walls are sheathed from one end to the other, the program can calculate the required reinforcement for the jacket. If a special value is desired, one of the steel mesh options can be used.
After exiting with the OK button, the jacket is drawn by clicking the first and second points on the wall axis to be jacketed.
Drawing of Reinforcement Jackets
1- In order to calculate the composite (with jackets) capacities of the walls in reinforcement, the reinforcement jackets and the walls should be defined from the same axis.
2-There is no need to change the Jacket Name in the Wall Reinforcement Jacket Properties. The program gives the element names automatically.
3- The wall thickness value is entered in the wall thickness to be jacketed box.
4- In case of outer wall jackets with left/lower protrusion length of the jacket, it may be appropriate to take half the thickness of the vertically inserted wall from the left or bottom of the wall to be jacketed. Left/bottom overhang length determines how far ahead or behind the left/bottom axis the mantle is defined. A positive or negative value can be given.
6- It may be appropriate to take the negative sign (for example, -10) of half the thickness of the wall that is perpendicular to the wall to be jacketed for interior wall jackets of left/lower protrusion length of the jacket. Left/bottom overhang length determines how far ahead or behind the left/bottom axis the mantle is defined. A positive or negative value can be given.
7- You can use the items (5) and (6) for the definition of the right/upper protrusion length of the mantle.
8-Concrete jacket thickness should be at least 3 cm in accordance with the Earthquake Regulation. Considering the rigidity of the jackets, the thickness of the jacket is one of the factors in determining the earthquake load that the jackets will take when static calculations are made.
9- Lower Level: If the floor you are modeling is the basement and your building is staggered, you can equate the lower coat level with the lower level of the wall.
10-Top Level: If the floor you are modeling is the Top floor and your building is staggered, you can equate the top level of the coat with the top level of the wall. If you enter the lower or upper level of the mantle different from the lower or upper level of the wall, the analysis results may deviate from the expected result.
11- In the building application, giving the upper or lower elevation of the jacket different from the lower or upper elevation of the wall may cause a decrease in the earthquake performance of your building.
12-You can activate the upper left face covering option to cover the left side of the wall on vertical walls and the upper face on horizontal walls.
13-You can activate the lower right side covering option to cover the right side of the wall on vertical walls and the bottom side of the wall on horizontal walls.
14- Mark the first and second ends of the mantle by clicking the OK Button and clicking the axis intersection points on the main modeling screen. The Mantle Will Be Drawn.
15- If you want to take into account the contribution of the Reinforcement Jackets to the wall pressure safety stresses or to calculate the Contribution of the Reinforcement Jackets to the Wall Shear Capacity, you should take the start and end points of the jackets on the outer walls equal or greater than the wall start or end points. (from formula definition)
15- If you want to take into account the contribution of the Reinforcement Jackets to the wall pressure safety stresses or to calculate the Contribution of the Reinforcement Jackets to the Wall Shear Capacity, you should take the starting and ending points of the inner wall jackets equal or greater than the wall starting or ending points.
Since the jacket will be drawn at the intersection of the jacket and the wall (the intersection of the jacket and the vertically inserted wall) on the screen and in the drawings, there will be an excess in the stiffness of the jacket as much as the wall intersection. However, this situation is taken into account in the analysis and since the mantle areas are reduced by the area of the intersection area, there is no difference in the calculations. It will be appropriate to trim (pruning, wiping) the jacket line separately at the jacket wall intersection in the drawings.
16-When the wall sheathing is drawn to cover the door or window space, the coats are automatically divided by the door or window spaces and the constructive coats are created automatically.
Constructive Reinforcement Mantle It is the continuation of the mantle in the wall parts above and below the window or above the door. Continuing the jacket in wall cavities increases the rigidity of the jackets in solid wall parts and provides better reinforcement in the building. Constructive jackets on the parts coming to the door or window while the reinforcement jackets are being drawn.
It is automatically created by the program and its properties can be changed by the user by changing the information in this form.
Mantle Accessories
If it is desired to use solid type reinforcement as sheath reinforcement in the building, first of all, in the reinforcement selection tab of the jacket properties window, mark the program as automatically selects, and in order to apply the maximum jacket reinforcement selected by the program as a result of the analysis, all jackets must be selected (with the option to change the properties of the selected jackets) to apply the maximum jacket reinforcement to all jackets. The maximum calculated steel mesh can be assigned to all jackets in the reinforcement selection tab of the window.
In the calculation reports, it shows that the reinforcement area, which should have a wire mesh in a class larger than Q785/785 steel mesh, cannot be provided with ready-made steel mesh. For example, if Q1234/1234 mesh is calculated, it indicates that 12.34 cm2/m horizontal and vertical reinforcement should be used in this jacket.
In such a case, 2 pieces of Q634 reinforcement (2*634>1234) can be used inside the mantle.
or
For example, if a single row of 12 mm diameter ribbed reinforcement is to be used, 100/(12.34/(1.2*1.2*pi()/4) =9 cm intervals
Or, if two rows of 12 mm diameter ribbed reinforcement will be used, the drawings can be edited by selecting the reinforcement with 2*100/(12.34/(1.2*1.2*pi()/4) =18 cm intervals.
2-Reinforcement by Adding Vertical Beam to Insufficient Walls
Checking the option in the picture above ensures the implementation of the following regulation item in the program.
After selecting the Include vertical beams in wall strength option, insufficient walls may become sufficient when vertical beams of sufficient cross-section are added to the wall.
3- Reinforcement with Fibrous Polymer Winding
Insufficient walls are selected, right-clicked on them, and the Change selected wall properties option is clicked.
In the wall properties window, go to the LP Wrapping Tab and select the "Apply Fibrous Polymer Wrapping Application in Horizontal Strips and/or the Cross-Fibered Polymer Application Between Wall Corners" option.
The values for the material to be applied are written into the boxes and the OK button is pressed.
After the analysis, it is checked whether the wall has become sufficient. If it is not sufficient, the analysis is repeated by changing the number of LP wrapping layers on one side, the number of LP coated surfaces (the wall is covered on 1 or 2 sides), the spacing of the LP strips from axis to axis, the width of the LP strip or the material / quality.
Static results can be checked from the wall shear stress report
Checking the option in the picture above ensures the implementation of the following regulation item in the program.
After selecting the Include vertical beams in wall strength option, insufficient walls may become sufficient when vertical beams of sufficient cross-section are added to the wall.
3- Reinforcement with Fibrous Polymer Winding
Insufficient walls are selected and right-clicked on them and click on Change selected wall properties.
In the table above, the wall shear strength (Vrd) is found by adding Vfy+Vfc values to the smaller of the Vrd1a, Vrd1b values for each load.
Vrd=min(Vrd1a,Vrd1b)+Vfy+Vfc
Drawings can be retrieved from the drawing selection window.
foundations
Since the regulation does not specify the effect of foundation deficiencies on the building in performance calculations, the program does not change the performance status of the building for foundation deficiencies. However, if the foundations are inadequate (checked from the foundation reports), analysis is made until the cross-sectional dimensions of the foundations are changed and sufficient, and reinforcement drawings are drawn separately by the user in order to reach the new sufficient foundation dimensions. Zekai Celep Teacher's Introduction to Earthquake Engineering book can be used for drawings.