disaster risk reduction in buildings ppt bal.pptx

8/19/2019 DISASTER RISK REDUCTION IN BUILDINGS PPT bal.pptx

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UTTARAKHAND

DISASTER RISK

REDUCTIONIN

BUILDINGS/HOUSINGSECTOR


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The mountainous region of Uttarakhand is part of the Himalayas, which areamong the youngest mountain ranges in the world. Consisting mostly of

uplifted sedimentary & metamorphic rocks and tectonically very active, theregion is extremely vulnerable to natural disasters, haards like earth!uakes,landslides, avalanches, cloudbursts, hailstorms, glacial lake out burst "oods#$%'s(, "ash "oods, lightning, and forest )res etc. have been a cause of ma*orloss to the region and the society.

+ncessant rain from - une /01 triggered , possibly due to the fusion of2esterlies with the +ndian 3onsoonal cloud system, resulting into "ash "oodsand landslides over a wide area.

The districts of 4ageshwar, Chamoli, 5ithoragarh, 6udraprayag and Uttarkashiwere the worst a7ected.

The nature8s fury manifesting into unprecedented damage and destruction was

most pronounced in the 3andakini valley of the 6udraprayag district. Torrentialrains coupled with melting of the Chorabari $lacier led to "ooding at the9edarnath :hrine and the ad*acent areas of 6ambara, ;gostyamuni, Tilwara,and $uptkashi. ther pilgrimage centres in the region, including $angotri,


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Consequences3ore than nine million people were a7ected.

; total of =>0 people died and oer !""# $eo$%e &erere$orted 'issin(

;bout ,=01 villages were a7ected, >,?>= cattle@livestock were

lost

,A1 houses were fully damaged

%arge number of tourists and local inhabitants were stranded inthe diBcult treacherous mountain terrain of upper reaches ofthe Himalayas

xtensive damage to housing, both in urban and rural areas, as

settlements were mostly concentrated along rivers

Damages to public buildings resulted in severe disruption ofbasic services such as education, health, women & child careetc


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I)*ACT O+

UTTARAKHANDDISASTER ONBUILDINGS


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Re%ie,

Uttarakhand has a highly varied topography with

snowEcovered peaks,

glaciers,

deep canyons,

roaring streams,beautiful lakes, &

few patches of dusty plains in the south.

Soi%s

Uttarakhand has various types of soil

+n north, the soil ranges from gravel #debris from glaciers( to sti7clay.

+n south, 4rown forest soilGoften shallow, gravelly, and rich inorganic content.

+n extreme southeastern part of the state, the Tarai soils are mostly

rich, clayey loams, mixed to varying degrees with )ne sand andhumus.

Geo(ra$-ica% ,eatures


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C%i'ate

The climate of Uttarakhand is temperate, marked byseasonal variations in temperature but also a7ected bytropical monsoons.

3ost of the state8s roughly =0 inches #,?00 mm( of annualprecipitation is brought by the southwest monsoon, which

blows from uly through :eptember.

'loods and landslides are problems during the rainy seasonin the lower stretches of the valleys.

+n the northern parts of the state, 0 to ? feet #1 to ?metres( of snowfall is common between December and3arch


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The foundation of buildings were eroded.4uildings fell due to landslides.

:ome buildings submerged in mud.

E++ECT on BUILDINGS


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:oil in Uttarakhand region is vulnerable toerosion .

a. Deforestation and clearing of vegetation forconstruction of hotels , shops, buildings etc. toincrease tourism lead to more vulnerability forerosion.

+ncreased surface "ow of river due to silt,boulders and debris e7ecting waterlevel.

a. Construction of dams

b. o 5roper disposal of

muck lead to increase in

silt and rocks in river.

c. 3ining activities

REASONS


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Iiew of Uttarakhand after disaster

• Haphaard construction of houses, hotels etc.a. Construction with no adherence to codesE

no proper spacing between houses , proper

geological survey of soil keeping in mindthe future prospect was not done.


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SCO*E +OR DISASTER RESISTANTDESIGNING AND CONSTRUCTION O+

BUILDINGS USING INDIGENEOUS)ATERIALS. SKILLS TECHNOLOG0

DURING RECONSTRUCTION O+

BUILDINGS IN UTTARAKHAND


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$eotechnical :urvey of the ;rea

E :tudying the impact of disaster on soil, :oil Testing and hence

geotechnical measures for the strength of soil

o haphaard construction in the areaE 5roper distance between houses as recommended in +ndian

standards

E Usage of !uality materials in which the stones present in the area

can also be used after proper testing their strength and porosity

The construction should not in the vicinity of river, i.e.minimum distance of 00 meters from the periphery of river.

'oundation should be designed according to area.

E 'oundation should rest on rock and not on soil, if the rock is toodeep then 5ile 'oundation can be used.

+f the area is highly vulnerable to landslide, the constructionshould be avoided as far as possible, in extreme conditionEproper measures to prevent landslides should be taken.


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5roper bracings should be provided in the building so as towithstand horiontal force of earth!uake

:oft :torey i.e., o 4racing lements in the ground "oor should be

avoided , as they become weak points during horiontal force.


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;void mixed systems of columns and structural masonrywalls, 'ramed structure should be preferred.

6einforcement in long masonry walls should take place as

it makes building strong.

$rade of concrete should be selected thoroughly after checking thesite conditions and admixtures should be added after taking intoaccount the minerals present in the soil .

Therefore proper land use planning should take place before anyconstruction.


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*OSSIBILIT0 +ORRETRO+ITTING

RESTRENGTHENING O+E1ISTING BUILDINGS

*RONE TO DISASTER


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*reention o, Soi% Erosion

Divert the discharge water away from slopes by constructinggutters and using sandbags.

a. +f there is no scope for diverting E especially in case ofnatural sources of waterEcontain its speed by building smalldams, to ensure that the amount of erosion is in check

Do not stop the water "ow altogether, as it will result in pressurebuildEup over a period.

Use "exible pipes and divert storm drain or street gutter in a safemanner rather than redirecting it down a slope.

5lant trees and small shrubs on the slope to prevent erosion.

a. There exist few species of plants with shallow roots whichare speci)cally used to protect the top layer of the soil inmountainous regions. For exampleJ 4uckwheat #Fagopyrumesculentum) , Common


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Retainin( 4a%%s2ith proper drainage of water , Concrete retaining wall, wood or stone

retaining wall will help to reduce landslide.

a. 6etaining wall should be properly designed & should be checked safeagainst earth!uake.

A%terin( t-e S%o$e Gradient The gradient of the slope should be reduced by removing the material from

upper part of slope to near the base.

5rofessional expertise is re!uired for the same.

Digging and piling garbage should be avoided.


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Anc-ora(e o, 3ui%din(5s &ea6

*arts• ;nchors can be provided forstrengthening the foundation or anyother part of building which isendangered to fall.

Stren(t-enin( o, +oundation o,Bui%din(s

)ass concrete Under$innin(• 4y digging boxes by hand underneath the foundation and

se!uentially pouring concrete in a strategic order thusstrengthening the footing .

*i%e ,oundation• 5ile foundations can be used for

strengthening the soil beneath thefoundation.


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Under$innin( 37 e8$andin( resin in9ection; mix of structural resins and hardener should be in*ected into foundationground beneath footings.

• The expanding structural resin mix would )ll voids and crevices,•

compacts any weak soil and then,• if the in*ection is continued, the structure above may be raised and

reElevelled.


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STRUCTURAL STRENGTHENING;ddition of reinforcing mesh on both faces of cracked

wall holding it to wall through spikes or bolts and thencovering it with cement mortar.

+n*ecting cement or epoxy like material into cracks

Stren(t-enin( o, 3ui%din(s a(ainstEart-qua6e ,orces


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• 6emoval of portions of cracked masonry walls and piers andrebuilding them in richer mortar preferably non shrinking.

• 2all openings should be less and if provided, proper peripheralreinforcement is necessary.

•

+ncrease the lateral strength by increasing column and wall area.• :lates and roo)ng tiles should be replaced with corrugated ironor asbestos sheeting.

• +nsertion of cross walls in unsymmetrical building should bedone to provide transverse support to longitudinal walls.


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• 5roper connections between roof or "oor and walls, betweenintersecting walls and between walls and foundation should beensured.

• ;nchors of roof trusses should be improved

NON STRUCTURALSTRENGTHENING

• 5atching of defects such ascracks and fall of plaster.• 6epairing doors , windows and

changing glass panes.

• Checking and repairing electricconduits@wires.

• Checking and repairing $as

5ipes, 2ater 5ipes and 5lumberservices• 6ebuilding nonEstructural walls,

chimneys, parapet walls etc.• 6earranging disturbed roo)ngtiles•

6eplastering of walls asre!uired.


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+ACTORS LEADING TO2ULNERABILIT0 O+BUILDING DURING

DISASTERS


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E%ack of maintenance of drains and waterways.

EConstructing new housing settlements withoutimproving the existing drainage system, thus

overwhelming the drainage system.

E%ocation of settlements in seismic areas, especiallyon poorly consolidated soils, on ground prone tolandslides or along fault lines.

E Unreinforced masonry buildings with heavy roofs

are more vulnerable than lightweight wood framedstructures.

EDense groupings of buildings with high occupancy.

E ot building homes on the right foundation

Buildings that lack structural integrity are more

susceptible to be damaged by a landslide than amore sturdy building.

E 4uried pipelines must be made from a "exiblematerial so that they would shift with the soilmovements and not be more prone to breakingwhen there8s soil movement

•Construction

without proper$eoEtechnicalknowledge of thearea

•Doing construction

without adherenceto 4uildingcodes@standards.

•Usage of low!uality

constructionmaterials.

•o proper landuse planning.

+LOODS

EARTH;UAKES

LANDSLIDES

INGENERAL


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CONSIDERATIONS +OR

SA+ER SUSATINABLEBUILDING *RACTICES


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5roper $eotechnical survey of the area and testing of soil should be

done.

5roviding proper Construction and xpansion *oints in the buildings.

Design should be done for :eismic conditions & other possible natural

disasters4uildings should be constructed on a safe distance i.e., minimum /00

meters from the river.

Cultivation of trees should be done especially near the river.

'oundation should be designed properly according to geotechnical

area.$rades of concrete should be used according to +:E-?= as in mild ,

moderate and severe conditions.

5roper cover @methods should be used to keep reinforcement freefrom corrosion.

7ective %and Use 5lanning should be done before construction.

:trict following of codes #+ndian :tandards( while construction, shouldtake place.

'ramed structures should be preferred.

4uildings should not be over rigid and should be light weight.


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CODES. STANDARDS.)ANUALS. GUIDELINES ETC<


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+: -?= K Code of practice for 6einforced Concrete

+: >A1 K Criteria for arth!uake 6esistant design of:tructures.

+: 1A1? K :eismic valuation, repair and strengthening ofmasonry buildingsE $uidelines

+: --?> E6etaining 2all 'or Hill ;reaE $uidelines

i. 5art JAA> K :election of Type of 2all

ii. 5art /J AA> K Design of 6etaining@4reast 2alls

iii. 5art 1 JAA> K Construction of Dry :tone 2alls

+: -=>0JAAAE %andslide ControlE $uidelines

;n arth!uake 5reparedness $uide K ; ready 6econer forHome Dwellers E +D3

:eismic Conceptual Design of 4uildingsE 4asic 5rinciples forngineers, architects, 4uilding owners, and ;uthorities KHU$ 4;CH3;


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=KNO4DISASTER

NO DISASTER>E Thank

disaster risk reduction in buildings ppt bal.pptx

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