Rittergasse 11, Basel - hamzaepfl/BSML GitHub Wiki

Building characteristics

3D street view

Geolocation: 47°33'20.7"N, 7°35'36.5"E

StreetView

General characteristics*

  • Address: Rittergasse 11, Basel Switzerland
  • Office building, commercial and administrative usage
  • Year of construction: 1901
  • Number of storeys: 3 without counting basement and attic
  • Construction volume: 7098 m3
  • Floor boundary area: 340 m2
  • Floor average net area: 280 m2
  • Assured value: 8 mio CHF

* Source: Kanton Basel-Stadt

Structural characteristics

  • Massive stone masonry shell (exterior and some interior walls)
  • Timber floor
  • Pitched roof
  • More massive stone masonry wall foundations

BIM model

BIM

BIM model (created on Revit) of the structure up to LOD 300 according to BIM Forum specifications, and based on the survey 2D drawings. Stairs have not been included in the structural model. The roof is modeled as an architectural element (without dormers), its substructure has not been modeled due to a lack of information on it. All openings have been approximated to be rectangular. Timber joists supporting the wood sheeting making the floor slabs were made spanning toward the shorter direction, their section and spacing have been hypothesized following woodwork standards (full workflow available in the *report).

EFM model, SAMUEL

EFM

Equivalent frame model created by Ivana Bozulic, based on the state of the art macro element formulation*. The discretization of elements has been generated using Francesco Vanin's tool (SAMUEL**) for analyzing the seismic behavior of unreinforced masonry structures.

* Source: Macro-element: Vanin F, Penna A, Beyer K (2019) "A three-dimensional macro-element for modelling of the in-plane and out-of-plane response of masonry walls,"
** Structural Analysis of Masonry Under Earthquake Loading, the software in not yet publicly available.

Seismic Analysis

Earthquake analysis performed through the OpenSees software.

Modal analysis have first been performed to get the fundamental period (0.305 s) and visualize the different modes behavior.

Mode 1 2 3 4 5 6
Period [s] 0.305 0.283 0.267 0.210 0.209 0.197
Behavior

Pushover analysis (rectangular distribution of forces) have been conducted in the two principal direction considering both senses. This gave us info on the capacity curve of the building which is then approximated bilinearly and used to assess the building to seismic case based on displacements.

Direction X+ X- Y+ Y-
Behavior
V_peak [kN] 6311 6678 6148 7105
d_peak [mm] 45 38 44 53
V_ult [kN] 5049 5343 4918 5684
d_ult [mm] 81 79 372 137
V_el [kN] 4418 4675 4304 4874
d_el [mm] 15 13 9 11

Illustration of the values extracted from the capacity curves:

LegendValues

More info in the *report

FEA model, Robot Structural Analysis

FEA

Model generated using the direct integration tool between Revit and Robot Structural Analysis.

Seismic Analysis

  • Modal Analysis

Seismic modal (6 modes) analysis in three directions, without accounting for eccentricities.

Mode 1 2 3 4 5 6 CQC
Period [s] 0.29 0.26 0.25 0.20 0.17 0.16 -
Total displacements Direction X
Total displacements Direction Y

Tri-directional combination, CQC:

https://github.com/hamzaepfl/BSML/blob/main/Historical%20buildings%20-%20Switzerland/Ritttergasse11Basel/FEM/RobotStructuralAnalysis/Images/cqcTridirectional.PNG

  • Pushover analysis

Robot Structural Analysis can not be trusted to perform nonlinear pushover analysis of unreinforced masonry buildings, as illustrated by the linear capacity curve given below which is completely absurd.

https://github.com/hamzaepfl/BSML/blob/main/Historical%20buildings%20-%20Switzerland/Ritttergasse11Basel/FEM/RobotStructuralAnalysis/Images/CapacityCurveX%2B.PNG

More info in the *report.