An experimental investigation for pullout response of a single granular pile anchor in clayey soil

The granular pile anchor foundation is an effective and economical foundation system to counter the pullout forces exerted in case of transmission towers or foundations in expansive soil. The pullout tests were performed to study the behaviour of a single granular pile anchor in the clayey soil bed. Tests were conducted in a steel tank of 1 × 1 × 1 m size with the help of loading frame arrangement. The pullout load required for upward movement equal to 10% diameter was considered as the pullout capacity of the granular pile anchor. In the parametric study, length and diameter of the granular pile anchor were varied to examine their effect. Number of anchor plates was also varied in few tests. The pullout capacity enhanced with an increase in the diameter and length to diameter ratio. The effect of the length to diameter ratio was appreciable up to the value of 10. However, no significant effect was found in the cases of multiple anchor plates. A relationship is proposed to predict normalized pullout capacity.

Mobile attachment for automated crack milling

In the dismantling of nuclear facilities, the decontamination and remote-controlled crushing of reinforced concrete is a central point. The main objective is to selectively remove the contaminated material in order to feed the remaining material, which in relation to the overall system or overall mass, represents the predominant part of the normal recycling cycle. For the surface decontamination of the upper millimeters, several methods are available that are constantly being optimized and further developed. However, there is a great need for research in the demolition and selective deep removal of reinforced concrete, e.g. in the case of cracks or eruptions into which contamination could penetrate, or the removal of metallic fixtures. The production of freely measurable surface geometries is a constant objective (Edelmann et al., 2018). The German “Defined removal of highly reinforced concrete” (DefAhS) research project was funded by the German Federal Ministry of Education and Research (BMBF) from October 2013 to the end of March 2018. In the course of the project, a new combination tool consisting of indexable inserts and impact lamellas was developed. With this method it is possible to remove highly reinforced concrete in one operation. The following property right could be granted: “Device for removing building material” (DE102015114122B3). Within the research project, concrete, reinforcement and fixtures (dowels, rails, anchor plates, pipe penetrations) could be successfully cut. It could also be shown that it is possible to remove several layers of steel reinforcement within a concrete matrix. The “Mobile attachment for automated crack milling” (MAARISS) research project has been running since November 2020. The hybrid milling technology developed in DefAhS is intended to form the basis for the milling drum used in MAARISS. The aim in MAARISS is, among other things, a new development of the extraction system directly on the removal unit and an automation system for use in a nuclear facility. Cracks are to be automatically milled over in order to enable subsequent clearance measurement by the staff on site. The physically very strenuous work of crack uncovering should be reduced to just one operator in a safe environment. The construction of a scaffold should be completely dispensed with and existing transport technology (forklift or lifting platform) should be used.

Anchor Plates Bonded on Reinforced Concrete: A Preliminary Experimental Investigation

During the last decades, different technologies to anchor steel elements in concrete were proposed. The present work presents the results of a preliminary investigation of a new connection characterized by single steel plates that are directly bonded on concrete surfaces. The anchor response was experimentally investigated under both tension and shear actions. Specific conditions influencing the behavior of the bonded assembly were discussed, with particular reference to the presence of cracks and crack cycling in concrete.

Finite Element Analysis of Anchor Leg Improved Trough Embedded Parts Based on ABAQUS

Reasonable and accurate simulations of failure behaviors of steel-concrete composite members with trough embedded parts is of great significance for the study of joint failure mechanism of prefabricated components in assembled buildings. Based on the implicit solution module of ABAQUS, the anchor legs of 5234 trough embedded parts are redesigned. The cylindrical anchor legs are designed as anchor plates with different diameter holes. The finite element model of the anchor leg of improved 5234 trough embedded parts and that of concrete are established. The mechanical properties of the specimens under bending and shear failure are simulated. And take a research on the improved trough embedded parts. The results show that the ultimate stress of concrete and the ultimate stress of embedded parts decrease first, then increase and then decrease with the increase of the diameter of circular hole, and the displacement of anchor leg of embedded parts decreases first and then increases with the increase of the diameter of circular hole. When the diameter of circular hole is 10.0 mm, the ultimate stress of concrete, the ultimate stress of embedded parts and the displacement of anchor leg are the smallest, and the mechanical properties of embedded parts are improved the most.