The Nuevo Leon building was part of the Tlaltelolco housing project. It was designed according to the 1942 Mexican code and constructed in 1962. This building consisted of 3 units separated by 10 mm expansion joints and each unit had 14 stories. The story...

Prepared By: Miguel Robles
Occupancy: Residential
Year Built: 1962
Height: 39.32 m
Number of stories: 14
Stories below ground: 0
Size: 9292.5 sqm
Original Code: 1942 Mexican Code
Modification: Unknown
Year Modified:
Code of Modification:
Lateral Load System: Other
Other Load System: Longitudinal direction: Moment frames formed by columns and the beams of a flat slab including the contributions of the waffle s
Vertical Load System: Other
Other Vertical Load System: Waffle slab supported on flat beams or bearing walls. Flat beams supported on concrete columns.
Foundation : Unknown
Other Foundation :
Country: Mexico
State: Distrito Federal
City: Mexico City
Street: Av. Paseo de la Reforma, UH Lopez Mateos (Tlatelolco)
Latitude: 19.450912
Longitude: -99.133383


 

Nuevo Leon bldg.

Earthquake Information

 

 

Earthquake Date 31309
Moment Magnitude 8.1
Epicentral Distance 385
Local Intensity VIII MMI
Site Description "Mexico City lies in the southwestern quadrant of a broad basin which was originally formed by block faulting of an uplifted plateau. It was subsequently blocked by successive lava flows that formed a dam across the valley just south of Mexico City. This dam resulted in the formation of Lake Texcoco, which slowly began to fill with silt, clay, and ash from nearby volcanoes. This lake bed has been used for the expansion of Mexico City. Today much of the city rests on lake deposits, which overlay older sedimentary sequences" (NBS, 1987).
PGA Lateral 0.17 (g)
PGA Vertical None (g)
SaT 0.22g north-south direction, 0.50g east-west direction.
Ground motion recording stations SCT (Secretara de Comunicaciones y Transportes).
Distance to station 6.5
Station Latitude 19.394
Station Longitude -99.148
Ground Motion Summary "The September 1985 Michoacn, Mexico earthquake occurred as a result of the subduction of the Cocos Plate along the Middle American Trench beneath the North American and Caribbean plates. The earthquake initiated at 18.2N, 102.6W, with a focal depth of approximately 18 km, and propagated approximately 170 km to the southeast. Because of the unrelieved accumulated strains caused by the slip movement (about 57 mm/year), the area was believed to have the potential for a major earthquake. A preliminary estimate of the seismic moment for the main shock is 0.9-1.5X10^28 dyne-cm (0.9-1.5X10^21 N-m), yielding a moment magnitude of 7.97 to 8.12 for the main shock" (NBS, 1987).

 

Damage Information

 

 

Performance summary

"The two northernmost wings collapsed apparently due to overturning when a failure was initiated on the east side of the structure near the foundation level toppling the building towards the east" (NBS, 1987).

Damage state description

"The two northernmost wings completely collapsed, supporting columns were sheared or pulled from the ground on the west side of the structure, leading to the toppling of the building towards the east, the pancaking phenomenon is clearly evident. The south tower sustained severe damage, failures occurred in the short column line on the east side, particularly on the levels used as a passageway between blocks every three stories" (NBS, 1987).

Summary of causes of damage

1. Ground floor columns on the east side lost their axial load carrying capacity due to the combined effects of strong beams/weak columns, short columns and soft story. 2. The loss of axial capacity of the east side ground floor columns started toppling the building towards the east. 3. The overturning of the building to the east pulled out the west side columns from the ground. 4. Period of the building may have been close to the period of the ground motion and the peak of the response spectrum acceleration. "Some foundations were underpinned after the 1979 earthquake. The resulting difference in foundations may have contributed to the collapse: the stiffening of the foundation on the east side of the building led to an asymmetrical response condition whereby the east side columns would have been subjected to relatively greater lateral forces. This asymmetry in column loading may have induced a failure of the first story east column line in the two northern structures, due to the relatively lower stiffness associated with the first floor lobby. Shearing of the columns would then occur either at underconfined joints or at the story mid-heights between the x-bracing" (NBS, 1987).

Observed Design and Construction Characteristics

 

Construction Quality

MaterialsNotesContribution to Damage
Concrete
Reinforcing steel

ExecutionNotesContribution to Damage
Conveyance/placement of concrete
Rebar
Field variance with design documents
OtherNotesContribution to Damage
Other Factors Construction Quality

Configuration

Plan IrregularitiesNotesContribution to Damage
Torsion "Some foundations were underpinned after the 1979 earthquake leading to an asymmetrical response" (NBS, 1987).
Perimeter boundary
Diaphragm
Out-of-plane offsets in lateral resisting system
Non-orthogonal systems

Vertical IrregularitiesNotesContribution to Damage
Soft story Soft first story
Weak story
Geometric variablility of lateral resisting system Braces staggered every 2 stories
In-plane discontinuity of lateral resisting system Braces not present at the lower stories
Mass distribution
Setback
Change in stiffness

OtherNotesContribution to Damage
Other Factors Configuration

Lateral Load Resisting System‐General

StrengthNotesContribution to Damage
Overall lack of strength

StiffnessNotesContribution to Damage
Extreme Flexibility

Load PathNotesContribution to Damage
Collectors/Struts Braces staggered every 2 stories
Anchorage of nonstructural elements
Out-of-plane capacity of walls
Diaphragm chords
Diaphragm openings

OtherNotesContribution to Damage
Other Factors Lateral Load Resisting System-General

Lateral Load Resisting System‐Frames

ColumnsNotesContribution to Damage
Shear strength
Flexural strength
Axial load ratio
Vertical load columns drift capacity
Interference of frame action by infill

BeamsNotesContribution to Damage
Strength relative to columns
Shear controlled behavior
Continuity of longitudinal reinforcing
Loss of vertical capacity
Interference of frame action by infill beams

JointsNotesContribution to Damage
Interior
Exterior
Corner

OtherNotesContribution to Damage
Other Factors Lateral Load Resisting System-Frames

Lateral Load Resisting System‐Shear Walls

ShearNotesContribution to Damage
Diagonal tension/compression
Sliding Shear
Flexure/shear

FlexureNotesContribution to Damage
Compression zone buckling capacity
Discontinuity of wall
Boundary reinforcing fracture/buckling
Boundary Reinforcing at openings

OtherNotesContribution to Damage
Other Factors Lateral Load Resisting System-Shear Walls

Lateral Load Resisting System‐Infills

InfillsNotesContribution to Damage
Unreinforced
Interference with frame action
Out of plane
Attachment to framing

OtherNotesContribution to Damage
Other Factors Lateral Load Resisting Systems-Infills

Lateral Load Resisting System‐Other

FoundationsNotesContribution to Damage
Liquefaction
Pounding Only a 10 cm gap is present between adjacent buildings
Surface Rupture

OtherNotesContribution to Damage
Pile/Pier tension capacity

MiscellaneousNotesContribution to Damage
Spread footing capacity
Other Factors Lateral Load Resisting Systems-Other-Foundations "Some foundations were underpinned after the 1979 earthquake" (NBS, 1987).

OtherNotesContribution to Damage
Other Factors Lateral Load Resisting Systems-Other-Misc

Repair and Retrofit Information

 

 

Type of Retrofit or Repair

None (demolished/abandoned)

Other Retrofit or Repair

Performance Level

Unknown

Hazard Level

Unknown

Retrofit or Repair Code

Unknown

Other Retrofit or Repair Code

Lateral Analysis

Unknown

Other Lateral Analysis

Design Strategy

Retrofit Summary

References

 

http://www.nist.gov/manuscript-publication-search.cfm?pub_id=908821
National Bureau of Standards (NBS), 1987. "Engineering Aspects of the September 19, 1985 Mexico Earthquake". NBS Building Science Series 165.


http://db.concretecoalition.org/static/data/6-references/MEXI001_Reference_01.pdf
Ohrui, S., Kanayama, H., Miyamura, M., 1988. "Simulation Analysis of Non-Linear Behavior of the Damaged Building in the Mexican Earthquake in Sept. 19, 1985". Proceedings of Ninth World Conference on Earthquake Engineering, August 1988, Tokyo, Japan.


http://db.concretecoalition.org/static/data/6-references/MEXI001_Reference_03.pdf
Petrovski, J. et al., 1988. "Influence of Soil-Structure Interaction on Dynamic Response of High-Rise Buildings in Mexico City due to September 19, 1985 Earthquake". Proceedings of Ninth World Conference on Earthquake Engineering, August 1988, Tokyo, Japan.


United States Geological Survey (USGS), 1985. "Mexico City Earthquake 1985". US Geological Survey Photographic Library, July 2012. http://libraryphoto.cr.usgs.gov/cgi-bin/search.cgi?search_mode=noPunct&free_form=mexico&free_form=1985&free_form=&free_form=


United States Geological Survey (USGS), 2008. "USGS ShakeMap: Michoacan, Mexico". ShakeMap Atlas, 2012.http://earthquake.usgs.gov/earthquakes/shakemap/atlas/shake/198509191317/


Edificios de Mexico. "Edificio Nuevo Leon". Edificios Demolidos de la Ciudad de Mexico, July 2012.http://www.edemx.com/citymex/demolidos/E_NvoLeon.html


"Mexico". 18.41 N and 102.37 W. Google Earth/USGS, 2012.