Design Considerations for Seismic Resistant Structures in Sabah

DESIGN CONSIDERATIONS for Seismic Resistant Structures in Sabah

12/01/15

Briefing prepared by: Ir. Simon SK GOH & TeamWANG HARON & GOH SDN. BHD.http://whgsabah.com Fb.com/whgsabah

INTRODUCTION

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GEOLOGY

Sabah Fault Lines nearest to Kota Kinabalu

About 58 km away at the Ranau/Kundasang area

The red lines denote the active Fault lines

FREQUENCY OF SEISMIC ACTIVITYFirst recorded in 1966 at a magnitude of 5.3 on the Richter scale in Ranau

1976 at a magnitude of 5.8 on the Richter scale in Lahad Datu

Last recorded in 1991 at a 5.4 magnitude tremor in the same area in Ranau

Recently, two active faults have been recognized at Ranau/Kundasang area

–Lobou-Lobou Fault, left-lateral strike-slip, trending N20oE

–Mensaban Faults, normal-oblique, striking WNW-ESE

EARTHQUAKE INTENSITY SCALERichter Scale (Magnitude) Modified Mercalli Intensity (MMI)

1.0 – 3.0 I

3.0- 3.9 II- III

4.0- 4.9 IV - V

5.0- 5.9 V-VI

6.0- 6.9 VI-VII

7.0- 7.9 VII- VIII

8.0 or Higher VIII or Higher

I = Not Felt II- III = Weak

VI= StrongVII = Very Strong

IV= LightV = Moderate

VIII = Destructive

I = Not Felt II- III = WeakIV = LightV = ModerateVI = StrongVII = Very StrongVIII = Destructive

Mercalli Intensity scale (MMI)

FACTORS AFFECTING SEISMIC DESIGN FORCES

• Ground acceleration

• Epicenter distance from a fault

• Site Geology

• Types of lateral load resisting system of structures

BASIC PRINCIPLES OF SEISMIC DESIGN

1. Structural Simplicity

2. Uniformity, Symmetry and Redundancy

3. Bi-directional Resistance and Stiffness torsional resistance and stiffness

4. Diaphragmatic Behavior

5. Adequate Foundation

SEISMIC RESISTANCE DESIGN CODES1. Design to EuroCode (EC8) based on ground conditions type and

seismic action zoning

2. Increase dead and imposed loads by 20% to allow for vertical movement

3. Increase Horizontal notional load from basic 1.5%g (deadweight)

4. Base Isolation System

COST IMPLICATION

1. Bigger columns / Shear wall

2. Increase in reinforcement

3. Foundation and Additional Tie-beams and foundation slab

4. Detailing for local ductility

5. Panel Walls, Finishes and ornaments to be permanently attached to the frame

RECENT EARTHQUAKE FACTS

Date: 5 June 2015 (Friday)

Origin time 07:15:43 MST

Duration: 30 seconds

Magnitude: 6.0 (Mw) (USGS)

5.9 (Mw) (MetMalaysia)

Depth 10.0 km (6.2 mi)

Epicentre 5.980°N 116.525°E

RECENT EARTHQUAKE FACTS

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Areas affected: West Coast & Interior Division (Mount

Kinabalu area), Sabah, East Malaysia

Total damage: Building and infrastructure damage,

landslides & geological changes

Max. intensity: VII (Very Strong)

RECENT EARTHQUAKE FACTS

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EPICENTRE:

KOTA KINABALU:

DO WE DESIGN FOR SEISMIC RESISTANCE?

1. “National Annex MS EN Standard EuroCode 1998 on Earthquake” – scheduled to be ready middle 2015?? When will it be adopted?

2. 11th June, 2015 – Newspaper reported IEM is working with SIRIM to develop a standard for Earthquake Resistant Buildings in Sabah Based on (Peak Ground Acceleration) PGA of 0.05g calculated for Kota Kinabalu based on 5Jun Quake

3. Malaysia is within low and moderate seismic region.

DO WE DESIGN FOR SEISMIC RESISTANCE? 4. What are the parameters to be

considered to Seismic Design ? a. Sub – Soil Profile b. Peak Ground Acceleration (PGA) c. Importance Classes for Buildingsd. Elastic Response Spectrae. Frequency Content of the Motion

DESIGN CONSIDERATIONS for Seismic Resistant Structures in Sabah

Briefing prepared by: Ir. Simon SK GOH & TeamWANG HARON & GOH SDN. BHD.http://whgsabah.com Fb.com/whgsabah

Thank you