Geohazard Earthquake

7/30/2019 Geohazard Earthquake

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Discussion Review

Restu Tandirerung

Ashadhien Noer Pratama

Lumigia Li Meco

Arif Wahyu Barokah


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outlin

e

Earthquak

e

Geohazard

Management

and

Mitigation

Introduction

Earthquake Elements

Surface Effects ofEarthquakes

Earthquake-ResistantDesign

Important Structur in hazard

area


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Earthquake

The occurrences:transform faults,convergen,divergen.

The surfaceeffects: faultsand crustalwarping,subsidence and

liquefaction, andtsunamis andseiches in waterbodies, etc.


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Earthquake Types

Plate-edgeearthquakes: Theboundaries of the

lithospheric plates aredefined by the principalglobal seismic zones inwhich about 90% ofthe worlds

earthquakes occur.

Intraplateearthquakes: Areasfar from the plate

edges arecharacterized byfewer and smallerevents, but largedestructiveearthquakes occurfrom time to timesuch as those of NewMadrid, Charleston,and northern China


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Plate-Edge Earthquakes

http://www.dynamicearth.co.uk


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Bantul, Yogyakarta,2006

http://andrigeosains.blogspot.com/p/pada-tahun-2004-gempa-dengan-kekuatan.html

Thecauses:

Opak faulthttp://rovicky.files.wordpres

s.com/2006/07/subduksi-

jawa.jpg


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1. The source of earthquake

2. Seismic wave types

3. Ground motion

4. Intensity and magnitude

Earthquake Elements


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The Source of Earthquake

Tectonic

earthquak

e

Most earthquakes occur along the plates

edge. The plates are driven by convection

motion of the material within the earth

mantle.


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The Source of Earthquake

Volcanic

activity


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Types of volcanic eruption

that cause the earthquake


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Seismic Wave

Types

Love wave

Reiligh

wavePrimary

wave

Seconda

ry wave


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Ground Motion,http://earthquake.usgs.gov/learn/glossary/?term=ground%20motion

Ground motion is the movement of the earth's surface from earthquakes orexplosions. Ground motion is produced by waves that are generated bysudden slip on a fault or sudden pressure at the explosive source and travelthrough the earth and along its surface.


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Intensity and Magnitude

Intensity is aqualitativevalue basedon theresponse of

people andobject on theearth surface.

Magnitude is aquantitativevaluecomputedfromseismogramdata.


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ATTENUATION

Attenuation is the decay or

dissipation of energy or intensity ofshaking with distance from the source


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Amplification

An increase in ground acceleration

with respect to base rockexcitation istermed the ground amplification

factor.


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Duration

the duration of strong ground

motion plays a direct role in the

destruction caused by anearthquake. it is a function of the

size of fault rupture and fault

type, path from the source to thesite and site geology


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Recurrence and Forecasting

forecasting the location,

magnitude and time of

occurrence of an earthquake isthe role of the seismologist and is

necessary for seismic design

and for the early warning of animpending event.


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Periode ulang 2475 tahun

P i d l 475 t h


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Periode ulang 475 tahun


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Surface Effects of Earthquakes

Fault:

offset


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Subsidence


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Liquefaction


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Slope Failures


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Tsunami & Seiches


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Volcano Hazard

Earthq ake Resistant


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1. Ground Motion

a. Dynamic Force

The large amounts of energy released

during earthquakes produce dynamic

forces result in transient deformations in

rock and other nearly elastic geologic

materials

b. Significance

The effect of the dynamic

forces, therefore, can be

divided into two broad

categories:

The effect on structures

The effect on the geologic

material itself

Earthquake-ResistantDesign

c. Field Measurement

Ground displacement

(amplitude) is measured by

seismographs.

The force imposed on

structures, is measured by


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KEmax = mv2 max = (W/g) v2max

Motion amplitude (displacement),frequency or acceleration (results

from combining amplitude andfrequency)

Force with which energy movesthe structure

Energy itself,defined in terms ofthe motion which it produces(kinetic energy)

S f D R l ti hi


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Surface Damage Relationships

2. Earthquake

destruction is

related to a number

of factors includingmagnitude,

proximity to

populated areas,

duration of theevent, the local

geologic and

topographic

conditions, and the


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a. GeneralCharacteristics

Reaction to Strong

Ground Motion

Energy Transmitted

to Structures

b. Response ModesStuctures exhibit various

modes of response to

ground motion depending on

their characteristics. Peak horizontal ground

acceleration

Vertical acceleration

Differential

displacements

Frequency

Duration of shaking or

repeated application of

forces

Structural Response


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c. Dynamic Reaction ofStructure

Source

Force on StructuralMembers

Single-Degree-of-Fredoom System

Multi-Degree-of-Fredoom System

Dynamic Response

Source

The dynamic reaction of a

structure to ground motion is

governed by its characteristic

period T or structural frequency

of vibration which is related to

structural mass, stiffness, and

damping capability.

Force on Structural Members

Result in stress and deflection instructure.

Dynamic Response

Defined by its displacement

history

R


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A response spectrum

is a plot o f themaximum values of

accelerat ion , veloc i ty,

and disp lacement

response of an inf in i te

ser ies o f sing le-

degree-of-freedom

systems subject to a

t ime-dependent

dynam ic exci tat ion,

such as but not

l im i ted to ground

ResponseSpectra

Response spectra

are used as input indynamic analysis of

linear elastic

systems, i.e., theyare a convenient

means of evaluating

the maximum lateralforces developed in

structures subjected

to a given base

motion.


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-0.200

-0.150

-0.100

-0.050

0.000

0.050

0.100

0.150

0 5 10 15 20 25

Waktu (detik)

Percepatan

(g)


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The method selected for dynamic analysis

varies from the relatively simple conventional

approach to comprehensive analytical

procedures. The selection depends upon thedegree of risk and hazard.

Structure Purpose and Type

Pertains to failure consequence Earthquake Occurrence and Magnitude

Pertains to the hazard

Seismic HazardAnalysis


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Comprehensi

ve Analyt ical

Methods

The combined influence of ground

accelerations, their frequency

contents, and, to some extent,

ground shaking duration, in relation

to the period and damping of the

structure, are considered in

comprehensive analytical methods.


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Deterministic Seismic Hazard Analysis

(DSHA)

Probabilistic Seismic Hazard Analysis(PSHA)

Time-History Analysis

Seismic Analysis Progression

D t i i ti S i i H d A l i (DSHA)


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Deterministic Seismic Hazard Analysis (DSHA)


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Probabilistic Seismic Hazard Analysis (PSHA)


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-0.200

-0.150

-0.100

-0.050

0.000

0.050

0.100

0.150

0 5 10 15 20 25

Waktu (detik)

Percepatan

(g)

Time-History

Analysis


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The design earthquake is normally defined as

the specification of the ground motion as a basis

for design criteria to provide resistance to a

moderate earthquake without damage, and to

provide resistance to a major event without

collapse.

The DesignEarthquake


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Standard Structures (Uniform

Building Code, 1997)

Design basis earthquake

(DBE) Operating basis

earthquake (OBE)Standard Structures

(USACE, 1999)

Operating basisearthquake (OBE)

Maximum design

earthquake (MDE)


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Thepurpose of a SSI analysis is to evaluate a

coupled bedrocksoilstructure system

including resonance and feedback effects, for

foundations on or below the surface.

How to model :

Half-Space Analysis

Finite-Element Method of Analysis

Soil-Structure Interaction (SSI)Analysis


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Identification

andtreatment ofgeologichazards

Estimation ofthe designearthquake

Establishmentof foundationdesign criteria

Evaluation of

structuralresponse todynamicforces

Detailed Study of Regional and Local


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Detailed Study of Regional and Local

Geologic Conditions

Fault Studies Prepare Geologic

Structure Map Investigate for

Capable Faults

Detailedreconnaissance andremotely sensedimagery interpretation

Fault zone extent andcontrol width

Exploration

Quaternary Dating

InvestigateOther Major

Hazards Flood potential

Slope stability

Ground subsidenceand collapse

Ground collapsefrom failure ofcavities in solublerock

Liquefaction andsubsidence potential

Site Soil andFoundationStudies Soil formations

Rock formations

Groundwaterconditions


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Evaluation and Analysis Ground Motion Prediction


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Evaluation and Analysis

Foundation Design andStructural response

Seismic Hazard Analysis

Foundation Evaluation and Selection

Seismic Input for Design Response


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Limitation in the Present State of the Art

Earthquake Characteristic

Surface faulting to intermediate and deep-

focus events

Well defined relationship between datadistribution and areal extent

Occurrence prediction based historical

activity not only last 100 or 200 years but

recent geologic time


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Limitation in the Present State of the Art

Ground Condition and Response

Fault Identification and Capability Evaluation Relationships

between fault displacement and Magnitude

Ground Response in term relationships among soil type, depth,

layering effects, bedrock boundary configuration, and response

characteristics of acceleration and frequency content must be

established

Dynamic Soil Properties

Evaluations of other soils must rely upon estimates of properties

from various correlation procedures.


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Thank for

Atention

Geohazard Earthquake

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