Abstract
Repetitive plate-loading test is intended to identify the elastic modulus of a target structure subjected to dynamic loading; such tests are mainly applied to railway roadbeds. The repetitive plate-loading test uses the same equipment as the plate-loading test but different loading methods. The plate-loading test derives the subgrade reaction modulus (k30), while the repetitive plate-loading test derives the strain modulus (Ev2). The former considers the scale effect of the loading-plate size, whereas the latter does not, thereby reducing the reliability of the results. Therefore, numerical analysis was conducted to propose a scale effect that can applied to field tests. First, to verify the 50-mm loading plate, a previous study comparing the results of the 300-mm loading plate in a field test was simulated by a numerical analysis, and the results were compared and analyzed. Next, the strain modulus was investigated according to the loading-plate size under subgrade conditions. An equation to estimate the scale effect applicable to loading plates with diameters of less than 762 mm was derived. The relationship between the calculated strain and elastic moduli was additionally analyzed.
Highlights
To control the quality of earthworks in the field, a plate-loading test for roads (KS F 2310, Korea) and a plate-loading test for railways (DIN 18134, Germany) are conducted in Korea
In the present study, a numerical analysis was conducted, and a correction factor for the scale effect of the loading plate of the repetitive plate-loading test was proposed through a parameter study on the diameter of the loading plate to mitigate the limitations of the aforementioned field-verification test
In the area of the loading plate modeled at the center of the analysis model, the load in the vertical direction to the subgrade with the same magnitude as the repetitive plate-loading test was simulated in a stepwise manner
Summary
To control the quality of earthworks in the field, a plate-loading test for roads (KS F 2310, Korea) and a plate-loading test for railways (DIN 18134, Germany) are conducted in Korea. To reinforce the soft ground during the construction of underground structures and tunnels, various injection methods have been researched and applied, including consolidation grouting for sand and weathered soil, and permeation grouting for weathered rocks with developed joints Their reinforcement effects are assessed in terms of the strength, bearing capacity, and stiffness [4]. In the present study, a numerical analysis was conducted, and a correction factor for the scale effect of the loading plate of the repetitive plate-loading test was proposed through a parameter study on the diameter of the loading plate to mitigate the limitations of the aforementioned field-verification test. The results were compared with those of the existing field-verification test, and the correction factor was investigated according to the subgrade condition by classifying the soils based on the cohesion and friction angle
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
