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CEN/TC226/WG1/TG1 Linkoping June 14, 2011 AN INSTRUMENT FOR MEASURING POST ANCHORAGE PERFORMANCE Vittorio Giavotto – LIRA srl Marco Anghileri - Politecnico.

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Presentation on theme: "CEN/TC226/WG1/TG1 Linkoping June 14, 2011 AN INSTRUMENT FOR MEASURING POST ANCHORAGE PERFORMANCE Vittorio Giavotto – LIRA srl Marco Anghileri - Politecnico."— Presentation transcript:

1 CEN/TC226/WG1/TG1 Linkoping June 14, 2011 AN INSTRUMENT FOR MEASURING POST ANCHORAGE PERFORMANCE Vittorio Giavotto – LIRA srl Marco Anghileri - Politecnico di Milano

2 Purpose Purpose Push tests on barrier postsPush tests on barrier posts Static and dynamic testsStatic and dynamic tests Acquisition of force and displacement dataAcquisition of force and displacement data Tests on posts on- siteTests on posts on- site Driving and extracting postsDriving and extracting posts CEN/TC226/WG1/TG1 Linkoping June 14, 2011

3 Dynamic test on hard soil Dynamic test on soft soil Driving and extracting post CEN/TC226/WG1/TG1 Linkoping June 14, 2011

4 Technical data Self propelling pole driver plus post testing equipment CEN/TC226/WG1/TG1 Linkoping June 14, 2011 Static test Force70 kN Stroke1600 mm Dynamic test Ram mass365 kg Max. velocity 12 m/s Useful stroke600 mm Impact energy 26 kJ Transducers 2 component load cell Accelerometers Position transducers Data acquisition 8 channels Max sampling rate 100 kHz Storage capacity 4 Gb

5 Testing CEN/TC226/WG1/TG1 Linkoping June 14, 2011 Static: the ram is slowly pushed by one hydraulic cylinder Dynamic: The ram is pushed to a high velocity by two air cylinders

6 6 posts dynamically tested CEN/TC226/WG1/TG1 Linkoping June 14, 2011

7 Problems in dynamic tests The post must be accelerated to the speed of the ram in a few millimetersThe post must be accelerated to the speed of the ram in a few millimeters Post acceleration can easily go over 1000 gPost acceleration can easily go over 1000 g High oscillations are initiated in the postHigh oscillations are initiated in the post Post oscillations and post inertia force introduce high disturbances in measurementsPost oscillations and post inertia force introduce high disturbances in measurements A post in a real barrier is not accelerated so abruptly: veicle and rail deformation allow centimeters fo the acceleration of the postsA post in a real barrier is not accelerated so abruptly: veicle and rail deformation allow centimeters fo the acceleration of the posts CEN/TC226/WG1/TG1 Linkoping June 14, 2011

8 Dynamic test (2100 frame/s) Visible bending oscillations of the postVisible bending oscillations of the post The cable activating the displacement transducer goes slackThe cable activating the displacement transducer goes slack Measurements are difficult to useMeasurements are difficult to use Low pass filtering does not helpLow pass filtering does not help

9 Dynamic test with a honeycomb cushion Post oscillations are strongly reducedPost oscillations are strongly reduced The cable of the transducer remains almost straightThe cable of the transducer remains almost straight The strain rate and the deformation of the post are not affectedThe strain rate and the deformation of the post are not affected

10 CEN/TC226/WG1/TG1 Linkoping June 14, 2011

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12 Comparison of static and dynamic tests on identical posts, HE100A S275JR, bolted on a rigid deck

13 Future activity - Research Tests of different posts in different soilsTests of different posts in different soils Behaviour of soils at different velocitiesBehaviour of soils at different velocities Difference between static and dynamic behaviourDifference between static and dynamic behaviour Correlation of post push parameters with alternative measurementsCorrelation of post push parameters with alternative measurements Development and calibration of numerical models for soil post interactionDevelopment and calibration of numerical models for soil post interaction CEN/TC226/WG1/TG1 Linkoping June 14, 2011

14 Future activity – Technical support Qualification of soils for barrier installationQualification of soils for barrier installation Data base for soil–post iinteractionsData base for soil–post iinteractions Validation of post depth increase as a compensation of soil weaknessValidation of post depth increase as a compensation of soil weakness Verification of anchorage performanceVerification of anchorage performance Contribution to the improvement of standardsContribution to the improvement of standards CEN/TC226/WG1/TG1 Linkoping June 14, 2011

15 Conclusions The new instrument is a very effective aid for research on soil-post interactionsThe new instrument is a very effective aid for research on soil-post interactions It can be used also to measure ultimate barrier anchorage loads on bridge decksIt can be used also to measure ultimate barrier anchorage loads on bridge decks The use of some kind of cushion in dynamic tests is strongly recommendedThe use of some kind of cushion in dynamic tests is strongly recommended The results of the research activity will be available to TG1The results of the research activity will be available to TG1 CEN/TC226/WG1/TG1 Linkoping June 14, 2011


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