This document discusses different methods for providing lateral load resistance in structures, including structural modifications, aerodynamic modifications, base isolation, and damping sources. It focuses on tuned liquid dampers, which use sloshing liquid in a container to dissipate vibrational energy. Tuned liquid dampers can be tuned to the natural frequency of a structure by adjusting their dimensions and work through sloshing of liquid in rectangular or cylindrical containers, usually filled with water. They provide effective damping against wind and earthquake vibrations at low cost and maintenance.

1. TUNED LIQUID
DAMPERS

2. LATERAL LOAD RESISTANCE
 structural modifications
 aerodynamic modifications
 base isolation techniques
 damping sources

3. STRUCTURAL
MODIFICATIONS
Outrigger system Belt bandage system

4. AERODYNAMIC
MODIFICATIONS
Fins Chamfered corners

5. BASE ISOLATION
Elastomeric bearings Sliding bearings

6. DAMPING SOURCES
 structural
 aerodynamic
 soil
 auxiliary

7. WHY AUXILIARY SOURCES?
 very less contribution of other sources
 difficulty in estimation
 adverse effects
 predictable & reliable

8. AUXILIARY SOURCES
 active
 passive
tuned liquid dampers
 semi active

9. TUNED LIQUID DAMPERS
 rectangular or
cylindrical
container
 liquid stored is
usually water
 sloshing water
dissipates
energy
 wind induced
vibrations

10. TUNING
 tuned to the natural frequency of the
structure
 achieved by adjusting the dimensions
 frequency equation

11. EFFICIENCY
 amplitude dependent
 placing on top floor
 floater beads
 torsion springs
 screens and baffles

12. ADVANTAGES
 low installation cost
 no moving parts
 low operation and maintenance cost
 frequency can be controlled by adjusting
height
 resistance against wind & earthquake
 temporary use

13. TYPES OF TLDs
TLD
TSD
shallow deep
TLC
D
LCVA DTLCD HTLCD PTLCD
CTL
D

14. TUNED SLOSHING DAMPERS
 single or a group of liquid stored
containers
 shallow and deep
 based on the ratio of depth of water to
that of the length in direction of vibration
 diameter in case of circular tanks
 < 0.15 shallow
 > 0.15 deep

15. TSDs (contd:)
 shallow TSDs has larger amplitude of
sloshing
 better damping at smaller vibrations
 non linear behavior at large scale
vibrations
 deep TSDs linear behavior even under
larger excitations
 water can be used for fire fighting and
emergency supply

16. APPLICATION
TSD unit Shin Yokohama Prince Hotel

17. TUNED LIQUID COLUMN
DAMPERS
 liquid stored in interconnected tubes
 an orifice provided in between
 motion of liquid mass in the tube
 pressure drop due to orifice
 unidirectional nature
 double TLCD

18. TLCDs (contd)
 shape advantage
 known behavior
 extra control by
dictating orifice
dimensions
 active control
 LCVA, HTLCD

19. APPLICATION
Cross section One Wall Center

20. CONTROLLABLE TLDs

21. CONCLUSIONS
 Effective against both wind and
earthquake
 TSDs suited for small scale excitations
 TLCDs are much more advantageous
 Control can be exercised for further
efficiency, but costly.