1. Introduction SLaMA-Approach

The Simple Lateral Mechanism Analysis - SLaMA - is a simple nonlinear analysis technique suitable for unreinforced masonry low-rise buildings with either rigid or flexible floors types. The SLaMA-approach is based on a mechanism-based failure modes for masonry, as described in NPR 9998:2018 (NPR) Annex G.6.2 for the in-plane (IP) assessment, and integrated with the NLKA and probabilistic methods, as explained in Annex H and J of the NPR, for the out-of-plane (OOP) evaluation. Floors and roofs are addressed following the New Zeeland seismic code of 2017 for the assessment of existing structures, section C8. Connections are checked according to the diaphragm actions found in the floor/roof and OOP. Foundations are checked according to the NPR chapter 10. The SLaMA-method is based on mean properties of materials and structural elements.

More background information about SLaMA and NLPO in general can be found in Paragraph 1.1 Introduction and 1.2 Non-Linear analysis methods and knowledge development of the NLPO/NLTH protocol on Gitlab and in Annex G.10 of the NPR.

1.1. References

The references with the additional information used in SLaMA-Approach are given in table below.

Table 1 - References
Reference number	Link
[1]	NLPO/NLTH Protocol Paragraph 1.1 Introduction and 1.2 Non-Linear analysis methods and knowledge development (see Introduction)
[2]	NLPO/NLTH Protocol Chapter 2 (see Phase 1 - Starting phase)
[3]	NLPO/NLTH Protocol Chapter 4 (see Phase 4 - Reporting)
[4]	NSCE assessment
[5]	L4-excelsheet
[6]	https://seismischekrachten.nen.nl/map.php

1.2. General SLaMA assessment workflow

The workflow consists of multiple phases. These phases are summarized in a flowchart and more in detail in the following chapters. For each phase, products are delivered (deliverables) that will be part of the final report.

Note

Store all your work in the appropriate Box-folders at all times. Preferably use Box Drive or the Box Sync.

Figure 1.7 Flowchart SLaMA assessment

1.3. Definitions and acronyms

Table 2 - Definitions and acronyms
Definition	Description
ADRS	Acceleration-displacement response spectrum (spectra)
Diaphragm	A horizontal structural element (floors and roof structures) that are connected to the vertical lateral force-resisting elements around it and that distributes earthquake lateral forces to elements, such as masonry walls, of the primary lateral system
NCE	Niet-Constructieve Elementen (Non Structural Elements)
NLKA	Non-linear kinematic analysis
NLPO	Non-Linear Push-Over
NSCE	Non-seismische constructieve elementen (Non-Seismic Structural Elements)
NPR	Nederlandse Praktijk Richtlijn (Dutch guideline for earthquake resistant design)
PRBE	Potential Risk Building Elements
PSSE	Primary and secondary seismic elements
SLaMA	Simple Lateral Mechanism Analysis (Type of NLPO)
Subsystem	Contains the lateral resisting elements, such as structural walls, that contributes to the in-plane seismic resistance in that axis. Also contains other structural elements of the structure that may not contribute to the resistance of subsystem but contributes as seismic mass according to a tributary area distribution
URM	Unreinforced masonry; A member or element comprising masonry units connected together with mortar and not containing any steel, timber, cane or other reinforcement

1.4. Element types

Elements can consist of primary, secondary, non-seismic structural and non-structural elements.

A primary seismic element is part of the system to withstand the horizontal effect of earthquake action. A secondary seismic element is an element that does not contribute to resisting the horizontal earthquake action but transfers the vertical loads from its own weight and connected elements (such as supported floors, roofs) to the foundations during the earthquake. The collection of the primary and secondary seismic elements is abbreviated to PSSE’s (Primary and Secondary Seismic Elements).

Non-seismic structural elements (NSCE, Dutch: Niet-Seismische Constructieve Elementen) are elements that are not part of the earthquake resistance system, but which are denoted as structural elements according to the Dutch Building Decree (Bouwbesluit, art. 1.5.1.7). Examples of NSCE are non-load-bearing interior walls, chimneys, parapets, stairs, balconies and gallery slabs. During an earthquake, an NSCE only has to transfer the earthquake load due to its own weight combined with the relevant quasi-permanent load to the foundation, whereby collapse of the structural element does not lead to progressive collapse. NSCE must be classified into four types (type 1 - 4). The vertical elements such as walls, roof curbs, chimneys, etc. are tested using the NLKA method, in accordance with Annex H of the NPR 9998:2018.

Non-structural elements (NCE) are elements that are not a structural element according to the building decree. Examples are suspended ceilings, pipes and cabinets. Non-structural elements do not need to be assessed. The NPR 9998:2018 does provide recommendations for the assessment of non-structural elements.

Table 3 - Local failure of construction part
	PSSE		NSCE	NCE
	Primary seismic elements	Secondary seismic elements	Non-seismic structural elements	Non-structural elements
Bearing walls	x	x
Steel structure		x
Steel structure braced bays and moment resisting frames	x
Concrete structure	x	x
Timber structure	x	x
Floors including ground floor and roofs	x
Non-load bearing masonry walls - near escape routes			x
Non-load bearing masonry walls - other			x
Balcony			x
Gallery			x
Gallery - escape route			x
Outer cavity leaf near escape route			x
Outer cavity leaf at height ≤3,0m			x
Platforms			x
Architectural steel			x
Lightweight non-load bearing partition walls			x
Lightweight non-load bearing partition walls - near escape route			x
Stairwell / stairs			x
Emergency stairwell			x
Facade elements (ornaments)			x
Canopies			x
Canopies near escape route			x
Atrium			x
Chimney (if no PRBE )			x
Roof curbs, statues (if no PRBE )			x
Roof curbs, statues near escape route (if no HRBE )			x
Ceiling				x
Heating, pipes etc.				x
Elevators				x
Cabinets (furniture)				x

x - probable category in which the building part falls, this must be assessed object-specific for each part.