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whe_example_nicaragua [2017/03/27 15:26]
Catalina Yepes [3. Buildings Process]
whe_example_nicaragua [2017/04/07 19:50] (current)
Vitor Silva
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-====== NICARAGUA, HOUSING REPORT======+====== NICARAGUA ======
 ===== Adobe walls supporting rough timber framed roof with corrugated iron sheeting ===== ===== Adobe walls supporting rough timber framed roof with corrugated iron sheeting =====
  
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 | Other |  |  |  | Other |  |  |
  
 +----
  
 === Design Process === === Design Process ===
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 **Expertise of those involved in the design:** **Expertise of those involved in the design:**
 +----
  
 === Construction Process === === Construction Process ===
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 **Construction issues** **Construction issues**
 +----
  
 === Building Codes and Standards=== === Building Codes and Standards===
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 **Additional comments on maintenance and building condition** **Additional comments on maintenance and building condition**
 +----
  
 === Construction Economics === === Construction Economics ===
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 **Additional comments section 3** **Additional comments section 3**
 +
 +{{:​wiki:​whe_3.jpg?​direct&​400 |}} {{:​wiki:​whe_4.jpg?​direct&​400|}} {{:​wiki:​whe_5.jpg?​direct&​400|}} {{:​wiki:​whe_5.jpg?​direct&​400|}}
 +
 +----
 +
 +==== 4. Socio-Economic Issues ====
 +
 +**Patterns of occupancy:​** The house is occupied by one family. It is used as a base from which the mother and daughter make food to sell on local buses as their source of income. During the evening, the whole family is present.
 +
 +**Number of inhabitants in a typical building of this construction type during the day:** <5
 +
 +**Number of inhabitants in a typical building of this construction type during the evening/​night:​** <5
 +
 +**Additional comments on number of inhabitants:​** ​
 +
 +**Economic level of inhabitants:​** Very low-income class (very poor)
 +
 +**Additional comments on economic level of inhabitants:​** House Price/​Annual Income (Ratio) 1:1 or better
 +
 +**Typical Source of Financing:​** Owner financedPersonal savingsInformal network: friends or relatives
 +
 +**Additional comments on financing:​** ​
 +
 +**Type of Ownership:​** RentOwn outrightOwn with debt (mortgage or other)
 +
 +**Additional comments on ownership:​** ​
 +
 +**Is earthquake insurance for this construction type typically available?:​** No
 +
 +**What does earthquake insurance typically cover/​cost:​** ​
 +
 +**Are premium discounts or higher coverages available for seismically strengthened buildings or new buildings built to incorporate seismically resistant features?:​** No
 +
 +**Additional comments on premium discounts:​** ​
 +
 +**Additional comments section 4:** 
 +
 +----
 +
 +==== 5. Earthquakes ====
 +
 +=== Past Earthquakes in the country which affected buildings of this type===
 +
 +^ Year ^ Earthquake Epicenter ^ Richter Magnitude ​ ^ Maximum Intensity ^ 
 +| 1972 | 12.400N | 6.2 | 6 (MMI) |
 +| 1985 | 11.725N | 6 | 6 (MMI) |
 +| 2004 | 11.424N | 6.9 | 6 (MMI) |
 +| 2005 | 11.198N | 6.6 | 6 (MMI) |
 +
 +----
 +
 +=== Past Earthquakes ===
 +
 +**Damage patterns observed in past earthquakes for this construction type:** Wall: The walls will crack in shear from lateral in-plane loads, or will fall in or out due to face-loads. In both cases, roof collapse may follow due to loss of wall support. ​
 +
 +Roof: The roof collapses due to lack of wall support and poor connections.
 +
 +**Additional comments on earthquake damage patterns:**
 +
 +----
 +=== Structural and Architectural Features for Seismic Resistance ===
 +
 +The main reference publication used in developing the statements used in this table is FEMA 310 “Handbook for the Seismic Evaluation of Buildings-A Pre-standard”,​ Federal Emergency Management Agency, Washington, D.C., 1998.
 +
 +The total width of door and window openings in a wall is: For brick masonry construction in cement mortar : less than ½ of the distance between the adjacent cross walls; For adobe masonry, stone masonry and brick masonry in mud mortar: less than 1/3 of the distance between the adjacent cross walls; For precast concrete wall structures: less than 3/4 of the length of a perimeter wall.
 +
 +{{:​wiki:​whe_7.jpg?​direct&​400|}} ​
 +
 +^Structural/​Architectural Feature ^ Statement ^ Seismic Resistance^
 +| Lateral load path | The structure contains a complete load path for seismic force effects from any horizontal direction that serves to transfer inertial forces from the building to the foundation. | FALSE |
 +| Building Configuration-Vertical | The building is regular with regards to the elevation. (Specify in 5.4.1) | TRUE |
 +| Building Configuration-Horizontal | The building is regular with regards to the plan. (Specify in 5.4.2) | TRUE |
 +| Roof Construction | The roof diaphragm is considered to be rigid and it is expected that the roof structure will maintain its integrity, i.e. shape and form, during an earthquake of intensity expected in this area. | FALSE |
 +| Floor Construction | The floor diaphragm(s) are considered to be rigid and it is expected that the floor structure(s) will maintain its integrity during an earthquake of intensity expected in this area. | N/A |
 +| Foundation Performance | There is no evidence of excessive foundation movement (e.g. settlement) that would affect the integrity or performance of the structure in an earthquake. | TRUE |
 +| Wall and Frame Structures-Redundancy | The number of lines of walls or frames in each principal direction is greater than or equal to 2. | TRUE |
 +| Wall Proportions | Height-to-thickness ratio of the shear walls at each floor level is: Less than 25 (concrete walls); Less than 30 (reinforced masonry walls); Less than 13 (unreinforced masonry walls); | TRUE |
 +| Foundation-Wall Connection | Vertical load-bearing elements (columns, walls) are attached to the foundations;​ concrete columns and walls are doweled into the foundation. | FALSE |
 +| Wall-Roof Connections | Exterior walls are anchored for out-of-plane seismic effects at each diaphragm level with metal anchors or straps. | FALSE |
 +| Wall Openings |  | TRUE |
 +| Quality of Building Materials | Quality of building materials is considered to be adequate per the requirements of national codes and standards (an estimate). | FALSE |
 +| Quality of Workmanship | Quality of workmanship (based on visual inspection of a few typical buildings) is considered to be good (per local construction standards). | FALSE |
 +| Maintenance | Buildings of this type are generally well maintained and there are no visible signs of deterioration of building elements (concrete, steel, timber). | FALSE |
 +
 +----
 +
 +=== Additional comments on structural and architectural features for seismic resistance ===
 +
 +**Vertical irregularities typically found in this construction type:** No irregularities
 +
 +**Horizontal irregularities typically found in this construction type:** No irregularities
 +
 +**Seismic deficiency in walls:** The adobe walls have limited tension resistance under seismic loads.
 +
 +**Earthquake-resilient features in walls:​** ​
 +
 +**Seismic deficiency in frames:​** ​
 +
 +**Earthquake-resilient features in frame:​** ​
 +
 +**Seismic deficiency in roof and floors:** The roof is poorly connected to the walls, and these poor connections ensure that it can not be counted on to act as a rigid diaphragm for the transfer of loads.
 +
 +**Earthquake resilient features in roof and floors:** The roofing material is lightweight,​ so the risk of injury from roof collapse is minimized.
 +
 +**Seismic deficiency in foundation:​** ​
 +
 +**Earthquake-resilient features in foundation:​** ​
 +
 +----
 +
 +=== Seismic Vulnerability Rating ===
 +
 +For information about how seismic vulnerability ratings were selected see the {{ :​wiki:​seismic_vulnerability_rating.docx | Seismic Vulnerability Guidelines}}
 +
 +|   ​^ ​ High vulnerabilty ​     ^^  Medium vulnerability ​     ^^  Low vulnerability ​     ^^
 +|   | A                   | B  | C                      | D  | E                   | F  |
 +| Seismic vulnerability class   | o                   ​| ​   |                        |    |                     ​| ​   |
 +
 +**Additional comments section 5 **
 +
 +----
 +
 +==== 6. Retrofit Information ====
 +
 +=== Description of Seismic Strengthening Provisions ===
 +
 +^ Structural Deficiency ^ Seismic Strengthening ^
 +| Walls | 1. Bamboo: Several researchers have been involved with using internal horizontal and vertical bamboo, in a fashion similar to reinforced concrete masonry walls. 2. Timber ring beam: This helps to hold the walls together and facilitate transfer of loads from the roof to the walls. 3. '​Improved Adobe' has long been promoted to make adobe buildings more robust under seismic activity. The '​system'​ does not utilise another material, but focuses on the design and planning of adobe buildings by limiting opening sizes, plan dimensions, wall lengths and heights, and roof weight |
 +| Roof | Adequate connections to a top timber or concrete ring beam and stronger connections in the framing itself will help the roof act as a diaphragm. Galvanized sheet metal is now common and helps reduces high loads. For thermal and aesthetic reasons, how ever, clay tile continues to be used. |
 +----
 +**Additional comments on seismic strengthening provisions:​** The bamboo strengthening scheme is not used in Nicaragua, but is presented here as an option for making Nicaragua buildings safer.
 +
 +**Has seismic strengthening described in the above table been performed?:​** Bamboo: Yes, it has been implemented in Peru with successful structural results, but unsuccessful local adoption of the concept. The system has not been used in Nicaragua. Timber ring beam: These are common now but often limited finances ensure they are out of reach for many in Nicaragua. '​Improved Adobe':​ Some principles are used, such as small openings and walls, but others are not evident, such as buttresses.
 +
 +**Was the work done as a mitigation effort on an undamaged building or as a repair following earthquake damages?:** All work done was only as part of the mitigation efforts.
 +
 +**Was the construction inspected in the same manner as new construction?:​** ​
 +
 +**Who performed the construction:​ a contractor or owner/user? Was an architect or engineer involved?:​** Technical assistance was used in the Bamboo implementation. Timber ring beams are often incorporated in new constructions by the occupants.
 +
 +**What has been the performance of retrofitted buildings of this type in subsequent earthquakes?:​** The bamboo system and timber ring beams have proven structurally successful in earthquakes.
 +
 +**Additional comments section 6:** 
 +
 +{{:​wiki:​whe_8.jpg?​direct&​400|}} {{:​wiki:​whe_9.jpg?​direct&​400|}} {{:​wiki:​whe_10.jpg?​direct&​400|}} {{:​wiki:​whe_11.jpg?​direct&​400|}} ​
 +
 +
 +==== 7. References ====
 +
 +Guidelines for earthquake resistant non-engineered construction IAEE National Information Center of Earthquake Engineering,​ IIT Kanpur, India 2004
 +----
 +An improved means of reinforcing adobe walls- external vertical reinforcement Dowling,D. & Samali,B. & Jianchun,L. Sismo Adobe, Lima, Peru 2005
 +----
 +Adobe and rammed earth buildings: design and construction McHenry,P. John Wiley and Sons, Canada 1984
 +----
 +Building with earth: a handbook Norton,J. Intermediate Technology Group, Warwickshire,​ UK 1986
 +----
 +Earthquake database search, [[http://​www.ngdc.noaa.gov]] National Geophysical Data Centre, Date accessed: 15/3/2006
 +
 +=== Authors ===
 +^ Name ^ Title ^ Affiliation ^ Location ^ Email ^
 +| Matthew A. French |  | Architecture,​ Victoria University of Wellington | 15 Landcross Street, Wellington 4001, NEW ZEALAND | emailformatthew @hotmail.com |
 +
 +=== Reviewers ===
 +^ Name ^ Title ^ Affiliation ^ Location ^ Email ^
 +| Andrew W. Charleson | Associate Professor | School of Architecture,​ Victoria University of Wellington | Wellington 6001, NEW ZEALAND | andrew.charleson@vuw.ac.nz |
 +
  • whe_example_nicaragua.1490621207.txt.gz
  • Last modified: 2017/03/27 15:26
  • by Catalina Yepes