Structural Systems Solvable Under RYTEİE2019 (Risky Building Regulation)

StatiCAD can analyze the following structural systems for risky building assessment under RYTEİE2019

1-Masonry (with Reinforced Concrete Slabs) (Internal Analysis) (Walls as Frame Finite Elements, Slabs as Shell FE): A finite element model is prepared for the 3D analysis of the structure. Masonry walls are modeled using frame (bar) finite elements at the centroid of the cross-section, while slabs are modeled using shell finite elements. Loads transferred from slabs to walls and other load-bearing elements are calculated using the finite element method.

In the program, walls, ring beams (horizontal bond beams), and vertical bond beams (participation of vertical bond beams in system stiffness is optional) are analyzed using frame finite elements. Slabs are divided into triangular meshes. Two separate methods can be used for triangular meshing. The preferred method (set as default) — "include only slab nodes in the slab triangular mesh" — divides the slab into 8 parts (meshes). Another method is the triangulated irregular network (TIN) method. In the TIN method, loads from walls resting on a slab can also be transferred to lower floors without drawing a beam. However, the application of this method (from the program user's perspective) requires more time and attention.

When transferring loads from slabs to walls through finite elements, slab loads are applied to slab nodes as dead load (G) in load case 0 and as live load (Q) in load case 1. When the stiffness matrix entries of the slab elements are placed into their positions in the global stiffness matrix, load transfers in the system are performed automatically. The program notifies the user whether there are any errors in load transfer from slabs to walls by comparing transferred loads with applied loads.

Load cases 2 and 4 are earthquake load cases in the X and Y directions respectively. Since no accidental eccentricity is applied under the RYTEİE 2019 regulation, load cases 3 and 5 (loads based on shifted center of mass) are not applied.

When RYTEİE2019 is selected, the program automatically sets the finite element solution options and restricts user intervention in analysis method choices to those specified by the regulation, preventing any modification. However, when the TBDY2018 method is selected, projects can be solved using classical methods or the finite element method, and different values and results can easily be tested.

2-Mixed Buildings: (If the masonry part is non-risky, the check per Equation 8.1 must be carried out separately in the technical report) (Internal Analysis): Reinforced concrete elements are also considered in the frame finite element solution. Forces acting on columns and walls are decomposed by the program. Since the masonry part is risky, the soundness of the reinforced concrete part alone cannot make the building non-risky according to Formula 8.1. If the masonry part is non-risky, however, the risk analysis of the reinforced concrete part must be performed with a program capable of analyzing reinforced concrete, and the risk assessment according to Formula 8.1 must be carried out separately, also taking into account the deficiency ratios in the masonry part.

3-Masonry Building with Timber Slabs or Without Rigid Diaphragm (Shell Finite Elements in SAP2000): In StatiCAD's internal analyses, rigid diaphragm assignment is applied in finite element solutions and modal analysis solutions (in the current version). For systems with timber slabs, however, RYTEİE2019 requires that the solution be performed without a rigid diaphragm (RYTEİE2019 Annex C.4 and 7.2.5).

In a structural analysis software, when performing analysis without a rigid diaphragm, a 100% mass participation ratio in modal mass participation cannot be achieved using the formula number of modes = multiplier × 3; therefore, the solution is performed by considering far more modes. For example, in a single-storey project, the calculation is carried out with 300 modes instead of 3. If necessary, the number of modes is increased to ensure that the ratio of effective masses to storey masses exceeds 90%.

Whether a package program uses a rigid diaphragm in modal analysis can be determined by checking whether more modes than the number of storeys × 3 are used. Other software claiming to perform analysis of masonry structures with timber slabs should also be checked to see whether the number of modes exceeds the number of storeys × 3 in the project.

StatiCAD requires the SAP2000 finite element software to perform analysis without a rigid diaphragm. On a computer with SAP2000 installed, StatiCAD opens SAP2000, transfers the structural model using shell finite elements. In SAP2000, it transfers the earthquake response spectrum curve via the Define > Functions > Response Spectrum command, also taking into account SS, S1, and the soil group. It instructs SAP2000 to analyze the building without creating any rigid diaphragm.

Taking into account the wall model and its segments entered in StatiCAD, it automatically creates Section Cuts in SAP2000. The Section Cut function in SAP2000 allows us to obtain the cross-section forces (Normal Force, Shear Force (V2, V3), Moment (M1, M2, M3)) for each wall as a single value by grouping the area (shell) elements divided into meshes. If Section Cut assignments had not been made, the results for each shell mesh and each node point would have needed to be taken separately and combined. The Section Cut process enables SAP2000 to perform this operation automatically.

When the "Get SAP2000 Results" button is clicked in StatiCAD, the P, V2, V3, T, M2, M3 results from the response spectrum analysis performed without a rigid diaphragm in SAP2000 are automatically loaded into StatiCAD's memory. The program then completes the risk analysis of the building according to RYTEİE2019 design criteria and SAP2000 static analysis results.

From StatiCAD calculation reports, SAP2000 rigid-diaphragm-free modal analysis results, wall cross-section forces calculated by SAP2000, and verification calculations performed using the risky building formulas can be viewed.

4-Masonry Building with Reinforced Concrete Slabs (Shell Finite Elements in SAP2000 with Rigid Diaphragm): In this method, modal analysis and seismic forces are determined in StatiCAD. After the structural model is transferred to SAP2000 and a rigid diaphragm is assigned, the seismic forces are applied to the rigid diaphragm. SAP2000 analysis results are automatically loaded into StatiCAD's memory and the risk analysis is performed.

5-Building with Some Reinforced Concrete and Some Timber Slabs (SAP2000: Create Diaphragm, Connect Selected Elements to Diaphragm, Perform Response Spectrum Analysis): StatiCAD transfers the earthquake response spectrum curve in SAP2000 via the Define > Functions > Response Spectrum command, taking into account SS, S1, and the soil group. In the response spectrum analysis method, the system can be solved with or without a rigid diaphragm. By defining a rigid diaphragm in the model, some elements can be connected to the rigid diaphragm and others can be left unconnected. User-selected walls, slabs, and vertical bond beams are connected to the rigid diaphragm. The connection of bond beams and wall segments above door/window openings (lintels) to the rigid diaphragm is determined based on the connection status of the adjacent wall. StatiCAD performs risk assessment based on SAP2000 cross-section force results and in accordance with the provisions of RYTEİE2019.