Alpine ski-bindings. Lateral release under impact loading. Test method

2015 ◽  
Keyword(s):  
Impact Loading ◽  
Test Method ◽  
Lateral Release ◽  
Loading Test

Multiple loading method for field testing drilled piers

1985 ◽  
Vol 22 (4) ◽  
pp. 592-599
Author(s):  
R. G. Horvath
Keyword(s):  
Test Procedure ◽  
Load Cell ◽  
Load Test ◽  
Test Method ◽  
Single Test ◽  
Loading Test ◽  
Shaft Resistance ◽  
Loading Method ◽  
Multiple Loading ◽  
Base Load

A multiple loading testing method is suggested, which permits testing a single drilled pier foundation under three different conditions of load support. The pier may be tested under conditions of combined shaft and end-bearing resistance, end-bearing resistance only, and shaft resistance only. The advantages of this multiple loading test method include observation of the load-transfer and displacement behaviours of the pier under these three different support conditions and verification of the values obtained for the components of load support, i.e., shaft and end-bearing resistance, all from a single test pier.A special base load cell capable of performing a different function during each cycle of loading is required. A suitable load cell, consisting of a series of Freyssi flatjacks, and the method of operation are described.A multiple loading test procedure was used successfully as part of a field investigation program on full-scale pier sockets in weak shale. Data on the load-displacement behaviour of the pier tested using the multiple loading method are reported. Information concerning piers tested using conventional single loading methods are provided for comparison.The multiple loading test results were in good agreement with results obtained from conventional testing methods. Thus the multiple loading test method provides an economical means of obtaining a large amount of design information for drilled pier foundation systems, using a single test pier. Key words: field load test, multiple loading, drilled piers and caissons, shaft resistance, end-bearing resistance, combined shaft and end-bearing resistances, base load cell, shale.

scholarly journals Freeze-Thaw Cycle Effect on Sputtering Rate of Water-Saturated Yellow Sandstone under Impact Loading

2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Yunbing Hu ◽  
Tianzhu Duan ◽  
Penghui Xian ◽  
Liang Chen
Keyword(s):  
Kinetic Energy ◽  
Specific Energy ◽  
Impact Loading ◽  
Freezing Temperature ◽  
Dissipated Energy ◽  
Particle Sizes ◽  
Loading Test ◽  
Freeze Thaw ◽  
Water Saturated ◽  
The Impact

In order to explore the impact of freeze-thaw temperature on the sputtering rate of water-saturated yellow sandstone under impact loading, in this paper, the Hopkinson pressure bar is used to conduct impact loading test on the water-saturated yellow sandstone at the same strain rate (74.22 s−1) under five different freeze-thaw temperatures. After impact loading, the yellow sandstone fragments are graded and screened by using the sizing screen, and the mass of fragments with different particle sizes after screening is counted. By transforming the fragments into spheres with the corresponding particle sizes, and combining the dissipated energy, the surface specific energy of yellow sandstone with different freeze-thaw temperatures is calculated. Finally, the sputtering rate of the fragments is obtained by using the relationship of total work, dissipated energy, and kinetic energy. The main conclusions are as follows: The freeze-thaw temperature has a significant effect on the fracture degree of yellow sandstone. The lower the freeze-thaw temperature is, the higher the fracture degree of yellow sandstone is, and the smaller the particle size distribution of fragments is. The fractal dimension of yellow sandstone increases with the decrease of freeze-thaw temperature, indicating that the damage of yellow sandstone is more serious. The dissipative energy of yellow sandstone increases with the decrease of freezing temperature, while the kinetic energy increases gradually when the freeze-thaw temperature is −30°C to −15°C and decreases gradually when the freeze-thaw temperature is −15°C to −5°C. The surface area and surface specific energy of yellow sandstone fragments both increase with the increase of freeze-thaw temperature. And the sputtering rate of yellow sandstone fragments increases gradually at freezing temperature from −30°C to −15°C and decreases gradually at −15°C to −5°C. Therefore, from the perspective of dynamic destruction process, the sputtering of yellow sandstone fragments at freezing temperatures of −15°C, −20°C, and −30°C is more intense than that at −5°C and −10°C. The results can provide some guidance for production in winter and winter regions.

scholarly journals A Novel Incipient Evaluation Method for Postconstruction Settlement by Using a Statistic Approach with Time-Extended Loading Test

2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Baoning Hong ◽  
Hao Shan ◽  
Xin Liu ◽  
Fenqiang Xu ◽  
Ke Sheng
Keyword(s):  
Field Test ◽  
Test Data ◽  
Evaluation Method ◽  
Early Stage ◽  
Test Procedure ◽  
Assessment Method ◽  
Assessment System ◽  
Test Method ◽  
Loading Test ◽  
Static Loading Test

This paper proposes an incipient assessment method for postconstruction settlement of highway subgrade by using statistical analysis approach with an improved static loading test method, time-extended loading test. The time-extended loading residual settlement Sr(t) and settlement rate Vs(t) are calculated from the field test data. The test procedure and the corresponding experimental validations are presented. Based on the field test data, a probabilistic model is built to bridge the final residual settlement and the actual postconstruction settlements. The proposed time-extended loading test based assessment system has been validated through three operating and well-documented road sections. According to the validation results, the construction quality can be accurately evaluated at an early stage and the corresponding remedial measures can be applied timely.

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