CM/LR(1)/HD/FD/NI/SP/LO/RF/NP/OS/GC/NN

Taxonomy string
CM / LR (1) / HD / FD / OS / RF / LO / SP / NN / NP / GC / NI
Construction Type
LBM: Load Bearing Masonry
GPSS Building Category
CM: Confined Masonry Walls
Country
El Salvador
GPSS Building Type
Taxonomy Parameters
Single storied

1. Height range

LR (1)

<p>Single story</p>

CM: Confined Masonry Walls

2. Main structural system

CM

<p>- Buildings constructed of masonry walls which are confined with reinforced concrete tie-columns and tie-beams<br>- Density of confinement affects seismic performance<br>- Masonry units are burnt clay bricks<br>- Walls are generally half brick thick at about 170 mm</p>

High design

3. Seismic design level

HD

<p>- Very good construction quality and workmanship<br>- Several seismic enhancement measures<br>- Building designed for a high seismic hazard zone<br>- Non-structural elements are designed to withstand lateral loads</p>

Flexible diaphragm

4. Diaphragm type

FD

<p>- Roof/floor with insufficient in-plane stiffness</p><p>- Poor connection of the roof/floor to the lateral load resisting system</p>

Original structure

5. Effective seismic retrofitting

OS

<p>- Original structure, which undertook or not minor non-structural improvements and/or maintenance</p>

Rigid foundation

6. Foundation type

RF

<p>- Prevents large foundation deformations and anticipated failures</p>

Large openings

7. Wall openings

LO

<p>- Opening width in a wall between two consecutive cross walls is more than or equal to 0.35 times (0.25 times) the wall length in single-story (multi-story) building</p>

No pounding

8. Seismic pounding risk

NP

<p>- Seismic gap between buildings at least 4% of the height of the shorter building where the expected collision occurs</p>

Good condition

9. Structural health condition

GC

<p>- Building structure is in overall good condition</p>

No irregularities

10. Structural irregularity

NI

<p>- Regular in plan and elevation</p>

Short panel

11. Wall panel length

SP

<p>- Wall length is less than or equal to 12 times the wall thickness</p>

Non-vulnerable non-structural components

12. Non-structural components

NN

<p>- Building does not have non-structural components that can produce human casualties and economic losses such as: parapets, ceilings, tiles, pipes, infill, etc.</p>

Failure Modes
Corner Failure

Corner Failure

<p>Corner failure mainly occur in heavy stone masonry walls. The corners are pushed out and subjected to partial collapse. Cause of this failure mode are poorly interlocking of the wall and mortar with poor quality.&nbsp;</p>

Non-Structural Failure

Non-Structural Failure

<p>Overturning or damage of non-structural components (e.g. parapets, chimneys, etc.) due to lack of adequate anchorage/confinement.&nbsp;</p>

Diaphragm Failure

Diaphragm Failure

<p>Collapse or failure of floor/roof. Possible causes include inadequate connection of floor/roof to the lateral resisting system (e.g. walls, frames), insufficient in-plane stiffness (e.g. unbraced timber/steel trusses) of the floor/roof, etc.&nbsp;</p>

In Plane – Combined Shear/Flexural Failure

In Plane – Combined Shear/Flexural Failure

<p>Walls are divided into piers (i.e. vertical elements) and spandrels (i.e. horizontal elements) by openings (i.e. windows and doors) in the wall. This failure mode is a combination of shear, flexural rocking, and shear sliding failure.&nbsp;</p>

In Plane – Flexural Rocking Failure

In Plane – Flexural Rocking Failure

<p>Walls are divided into piers (i.e. vertical elements) &amp; spandrels (i.e. horizontal elements) by openings (i.e. windows and doors) in the wall. Flexural rocking usually occurs when material shear capacity is high, piers are slender, and compressive stress is low in the wall. Flexural cracking develops at the heel of the pier, leading to rotating behavior of the wall about the toe.&nbsp;</p>

In Plane – Shear Failure

In Plane – Shear Failure

<p>Walls are divided into piers (i.e. vertical elements) and spandrels (i.e. horizontal elements) by openings (i.e. windows and doors) in the wall. Diagonal cracking can develop in piers with relatively small aspect ratio (i.e. effective height by width ratio), leading to degraded strength of and potential shear sliding resulted offsets and overturn of the wall.&nbsp;</p>

In Plane – Shear Sliding

In Plane – Shear Sliding

<p>Walls are divided into piers (i.e. vertical elements) and spandrels (i.e. horizontal elements) by openings (i.e. windows and doors) in the wall. When pointing mortar fails under shear, horizontal or stair-stepped diagonal cracks are generated, which allow sliding to occur. This may lead to potential offsets and overturn of the wall.&nbsp;</p>

Out of Plane Failure

Out of Plane Failure

<p>Overturning of masonry walls leading to partial or full collapse of the wall, which may have combined tension failure of in-plane pier portions of perpendicular walls. Possible causes are lack of structural integrity to achieve box-like behavior (e.g. no band beams, flexible diaphragms, etc.), and/or mortar has poor cohesion and tension capacity.&nbsp;</p>

Vulnerability