Building Damage Monitoring Techniques and Methods for Differential Settlement Control

1. Why Monitor ? • Measure Rate of Movement • Check Success of Remedial Action • Establish Cause of Damage

2. Monitoring Techniques Two aspects : • measuring the damage to see if it is getting worse (or better) • measuring the movement of the building to see which parts of the foundations are moving and at what rate * sometimes desirable to measure the movements in the ground directly

3. Crack Width Monitoring • Steel rule • Magnifier and graticule • Plastic tell-tales • Demec points • Brass screws

4. Examples : measurement using pencil marks measurement using a crack measuring gauge

5. Magnifier and Graticule

6. Plastic tell-tales

7. Demec Points Demec studs with gauge

8. Brass Screws

9. Monitoring Levels • Done using a precision optical level to record the movements of monitoring points fixed to the building. It is essential to use a precision instrument for these measurements to achieve an overall accuracy of + 0.5mm. • levels should be measured relative to a fixed reference point or datum

10. Monitoring Levels

11. Monitoring Lateral Movements • Technique : to install a special plastic tube in a borehole about 15m deep. • Movement of the tube from the vertical can then be measured by lowering an inclinometer down the tube. • The technique is highly specialized and should only be performed by a firm with the necessary expertise.

12. Monitoring Lateral Movements inclinometer

13. Different types of Settlement Sensors

14. Model 6302 VW Horizontal Inclinometer

15. Controlling the differential settlement of a buildingwith a flexible concept and reliable technology : • The settlement of a completed building is monitored and is rectified • if differential settlement occurs. • This modification method for differential settlement is an integrated • method comprising four subsystems • highly accurate settlement prediction • reduction of differential settlement • automatic settlement measurement • differential settlement rectification.

16. Controlling the differential settlement of a building with a flexible concept and reliable technology : • The difference between settlement of a building at the edge (A) and the center (B) often causes damages to both the functional and structural aspects of the building. This amount of differential can be accurately estimated.

17. Controlling the differential settlement of a buildingwith a flexible concept and reliable technology : • Measures to decrease the difference in settlement are provided in the ground, the foundation and the upper structure.

18. Controlling the differential settlement of a buildingwith a flexible concept and reliable technology : • The amount of differential settlement after a building is completed is automatically measured and controlled from a central monitoring room.

19. Controlling the differential settlement of a buildingwith a flexible concept and reliable technology : • When the difference exceeds the control value, the building can be returned to an even horizontal position by using hydraulic jacks fitted to the column bases and can be interfaced to maintain this integrity under reaction force.

20. Controlling the differential settlement of a buildingwith a flexible concept and reliable technology : Example of ground settlement observation(Rokko Athletic Indoor Hall at Konan University)

21. Application of Modification Method of Differential Settlement Rokko Athletic Indoor Hall at Konan University Canadian Academy

22. Application of Modification Method of Differential Settlement Rokko Distribution Center in Ryoden Unyu Royal International Air-Catering Co. Ltd