CASE HISTORYDOHA RED LINE NORTH

-CONTROL IN EXECUTION OF SYSTEM PERFORMANCE OF

CONNECTION AND GASKET  Emissione Data Approvazione Progetto Rev.

S. LUPI 27/10/2014 G. BOMBEN DOHA RED LINE NORTH 1

CASE HISTORY

INTRODUCTION

Fama Spa is an Italian company operating since 1988 in design, certification, manufacture of products for precast lining of tunnels. Fama Spa is specialized  in  the development of sealing systems and a wide range  of  accessories  for  the  connection,  lifting  and  anchoring  systems  for the construction of tunnels with TBM. 

For the excavation of the Red Line North di DOHA, FAMA SpA provided the gasket UG027A and the connection systems SmartBlock 90-160 300-60.

To complete a strategic path that began with the design and continued with the  certification  through  laboratory  tests,  with  a  campaign  of measurements,  it  was  possible  to document the performance of these products in exercise.

CASE HISTORY

DOHA METRO RED LINE NORTHDESIGN OF THE LINING

- UNIVERSAL RING 6+1- KEY 1/3 OTHER SEGMENT- EX. DIAMETER 6.770 mm- IN. DIAMETER 6.170 mm- THICKNESS OF CONCRETE 300 mm- LENGTH OF CONCRETE 1.500 mm

- ANCHORED GASKET 26 x 17 mm WITH HIDROPHYLIC STRIP

- 19 CONNECTORS FOR RING (3 FOR EACH SEGMENT , 1 FOR THE KEY)- GUIDE BAR AND BOLT ON THE

RADIAL JOINT

CASE HISTORY

EPDM SEALING GASKET

- UG027A

- ANCHORED GASKET 26 x 17 mm WITH HIDROPHYLIC STRIP

- PRESSURE REQUIRED TO CONTRACT 10 bar GAP 5 mm OFFSET 10 mm

CASE HISTORY

CONNECTION SYSTEM

- SMARTBLOCK 90-160/300-60- PULL OUT 90 KN- SHEAR STRENGTH 160 KN- LENGTH 300 mm- DIAMETER OF CENTERING 60 mm

CASE HISTORY

1. We want to calculate the current state of misalignment and separation of the joints between the segments in the gallery;

2. The relief is performed with the use of two measurement gauges: one for the depth, with which recalculate the offsets and one for the width of the slots for the recalculation of the gap;

3. The measurements of gap and offset are performed at about 20 mm from the T-joint, where maximums are the deviations from the nominal.

4. The joints are first classified according to the orientation angle to the progress of the excavation;

5. Usually the relief is performed on a continuous succession of five joints, reached by the operator that runs through the tunnel by foot. In case of severe anomalies the relief can be conducted on the entire ring with the aid of suitable lifting equipment. The measuring block 5 of joints may, at the operator's discretion, be repeated several times;

6. The sequence of measurements, if necessary, can be performed on the right side and on the left side of the tunnel with reference to the direction of advance of the excavation;

7. May be conducted in the presence of detections punctual infiltration of water, in order to evaluate if this is generated by an excessive misalignment, or spreading of the coupling or, finally, from other causes;

8. If necessary measurements can be performed on the blocks, facing the opposite of progress to compare with those initial misalignment stabilized along the tunnel.

9. On following the demoulding the segments undergoes a series of finishing treatments and surface covering which involve a thickening of the surface of the segment of some tenths; this causes a negative result in the recalculation of some gaps measured in the tunnel (physically impossible phenomenon). To eliminate this kind of alteration of the measurement, the measured gap values are increased by 0.5 mm.

PROCEDURE FOR DETECTION GAP AND OFFSET OF THE JOINTS BETWEEN THE SEGMENTS INTO THE TUNNEL

CASE HISTORY

PROCEDURE FOR DETECTION GAP AND OFFSET OF THE JOINTS BETWEEN THE SEGMENTS INTO THE TUNNEL

The measurements  of  gap  and  offset  are  performed  at  approximately  20 mm from the T joint, where the deviations from nominal are maximums.

MEASUREMENTS OF GAP

MEASUREMENTS OF OFFSET

CASE HISTORY

PROCEDURE FOR DETECTION GAP AND OFFSET OF THE JOINTS BETWEEN THE SEGMENTS INTO THE TUNNEL

In the diagrams below are identified types of angles between segments of a same ring adjacent each other refer to the direction of excavation.

CASE HISTORY

PRESENTATION OF RESULTSMEASURES OF GAP IN THE CIRCUMFERENTIAL JOINTS

CASE HISTORY

PRESENTATION OF RESULTSMEASURES OF GAP IN THE LONGITUDINAL JOINTS

CASE HISTORY

PRESENTATION OF RESULTSMEASURES OF OFFSET IN THE CIRCUMFERENTIAL JOINTS

CASE HISTORY

PRESENTATION OF RESULTSMEASURES OF OFFSET IN THE LONGITUDINAL JOINTS

CASE HISTORY

PRESENTATION OF RESULTSPICTURES OF THE TUNNEL

CASE HISTORY

ANALYSIS OF THE RESULTSASSESSMENT OF THE EFFICIENCY OF THE CONNECTION SYSTEMThere have been 294 measurements of gap and offset. 

The average weigth gain of the gap is 0.4 mm, the offset of 1.4 mm.

The requirements of the specifications of the Doha Metro Red Line North provide a mounting tolerance of 5 mm on the opening of the  joint (gap) and 10 mm on the  misalignment  of  the  joint  (offset).  The connection system SmartBlock allowed a mounting error is much lower than expected.

The connection system SmartBlock has minimized the effect of the divergence of the longitudinal and circumferential joints generated by the thrust of the gasket.

The performance of  the pull-out and  shear of  the SmartBlock are  suited  to  the conditions of employment, ensuring the correct dimensioning of the system.

CASE HISTORY

ANALYSIS OF THE RESULTSASSESSMENT OF THE EFFICIENCY OF THE SEALING GASKET

The gallery of the DOHA METRO RED LINE NORTH is dry.

The gasket sealing UG027A has been tested at the University "Tor Vergata” in Rome – Department of Civil Engineering – Structures and Material Tests Laboratory - for the hydraulic performance requirements in the specifications of the project Doha Metro Red Line North.

The gasket UG027A requires a  load of 45 KN/m for its complete compression facilitating, in fact, the permanence of the closed joint.

The anchoring in the concrete of the UG027A and angles conformed to the geometry of the segment, allow, during assembly of the ring, to remain in its seat.

CASE HISTORY

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