Computed tomography (CT) technology is a kind of nondestructive image reconstruction technology. CT visualization technology is introduced into the physical model test of a single pile, which can visualize a rock-socketed pile in soft rock under different pile top loads. In this article, the visualization process of a model test of a rock-socketed pile in soft rock is carried out by medical CT. The implementation procedure, the composition of the device, and the technical requirements of the test equipment, as well as the CT scanning operation of nondestructive visualization technique of the single pile model test, are introduced in detail. The influence of a marked layer setting, side wall effect, size of the model cylinder, and model pile on the visualization effect of a single pile model test is discussed. The feasibility and reliability of the model test visualization technology of a rock-socketed pile in soft rock are demonstrated by examples, and the failure mode of rock-socketed pile in soft rock is intuitively revealed to be the spherical cavity expansion mode of the pile end.
Fluidized solidified soil (FSS) has emerged as a promising material for marine pile scour remediation, yet its limited construction window and vulnerability to hydraulic erosion before sufficient curing constrain its broader application. This study systematically evaluates FSS formulations based on dredged sediment, cement partially replaced by silica fume (i.e., 0%, 4%, 8%, and 12%), and quicklime activation under three water–solid ratios (WSR, i.e., 0.525, 0.55, and 0.575). Experimental assessments included flowability tests, unconfined compressive strength, direct shear tests, and microstructural analysis via XRD and SEM. The results indicate that SF substitution significantly mitigates flowability loss during the 90–120 min interval, thereby extending the operational period. Moreover, the greatest enhancement in mechanical performance was achieved at an 8% SF replacement: at WSR = 0.55, the 3-day UCS increased by 22.78%, while the 7-day cohesion and internal friction angle rose by 13.97% and 2.59%, respectively. Microscopic analyses also confirmed that SF’s pozzolanic reaction generated additional C-S-H gel. However, the SF substitution exhibits a pronounced threshold effect, with levels above 8% introducing unreacted particles that disrupt the cementitious network. These results underscore the critical balance between flowability and early-age strength for stable marine pile scour repair, with WSR = 0.525 and 8% SF substitution identified as the optimal mix.
4 November 2018 in European Journal of Environmental and Civil Engineering
Using the model test technology of the rock-socketed pile in soft rock in consideration of the influence of the overburden, the physical model test with different overburden pressure and different rock-socketed depth is carried out. The vertical bearing mechanism and law of the rock-socketed pile in soft rock are analysed through the results of axial force distribution, shaft resistance distribution, load sharing ratio of shaft resistance and base resistance, shaft resistance relationship between shaft resistance and displacement, and relationship between base resistance and displacement, etc. Based on the accurate qualitative analysis of indoor model test results, and combined with the measured data and engineering experience at home and abroad, the vertical bearing characteristics of the rock-socketed pile in soft rock are comprehensively interpreted, and the vertical bearing mechanism and its influencing factors of the rock-socketed pile in soft rock are revealed.