Different content of foaming agent in the lightweight aggregate concrete test, the apparent density and compressive strength of concrete assessment indicators. Studies have shown that, with the dosage increase, the variation of the apparent density of the concrete is first decreases and then increases when the content is 0.8kg/m3 dry apparent density minimum; as the foaming agent content continues to grow, dry apparent density continues to increase, but the magnitude of increase is less obvious. At this point, its 28 days compressive strength of only 0.7MPa, the wall strength of the material does not meet the insulation requirements. Taking into account the apparent density and strength of wall insulation materials, requirements, test data to determine the optimal dosage of the foaming agent should be 0.4 ~ 0.6kg, to determine the content of foaming agent in the lightweight aggregate concrete of the most good range.
Similar model experiment under confining pressure, research latticed shell lining the mechanical properties and the carrying capacity of new support for the underground engineering - network shell support, according to the model experiments and theoretical. Test results prove that the the latticed shell supporting structure has good mechanical properties and a high level of support is a reliable form of support. Can make up for the deficiencies of the existing soft rock roadway structure, calculated to provide a reliable basis for mesh shell lining theoretical analysis.
Cable Anchor Supporting mechanism theory analysis, combined with high geostress, composite roof and complex geological conditions, the deep well under conditions of coal roadway by small aperture, anchor on the form of the structure and high prestressed construction technology, engineering practice shows that the technology is simple and applicability,is deep well solve the high stress soft rock tunnel, large sections into bifurcation point supports of the effective way of the problem. Not only reduces the support cost, reduce the workload of the Lane repair, and also greatly reduce the labor intensity of construction personnel, improve the reliability of the engineering safety. Accumulated experience, has broad application prospects for the deep well under the conditions of the other coal mine soft rock roadway
This paper describes a generalized modelling technique for the simulation of rock anchors, including mechanically anchored rock bolts, grouted rebars and cable bolts. The proposed technique is implemented in a two-dimensional, finite-element method. A rock anchor system is modelled by a series of bar elements, representing the anchor, which are connected along their length to the rock mass by continuous shear springs, representing the shear bond stiffness of the grout and the rock–anchor interface. Surface anchorage, anchor tensioning and full or partiallength grouting can be modelled. The versatility of the proposed model is illustrated by a simple example of a rectangular excavation, and the application of the model is demonstrated by a case study of an underground mine stope in hard rock, supported by cable bolts. Cet article présente une technique généralisée de modélisation numérique pour la simulation des boulons d'ancrage, incluant des boulons mécaniques, des armatures cimentés et des câbles d'ancrage. La technique proposée est effectuée par la méthode des éléments finis. Le système d'ancrage est modélisé par une série d'éléments linéaires, qui représentent l'ancrage, et qui est connectée au massif rocheux par des ressorts de cisaillement à l'interface rocheboulon. On peut modéliser l'effet d'ancrage de tête du boulon, et les boulons qui sont partiellement ou complètement cimentés. La polyvalence du modèle proposée est illustrée par un exemple simple d'une excavation rectangulaire. Une application pratique du modèle est présentée dans le cas d'un chantier d'abattage souterrain supporté par des câbles d'ancrage dans une mine de roche dure.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.