• Journal of Ocean Engineering and Technology
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• v.16 no.5
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• pp.49-55
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• 2002

The compression anchor is characterized by decrement of progressive failure, simple site work, economy and durability compared with tension anchor. In this paper, compression anchor is analysed through the laboratory element tests. The formula to be estimate the grout strength in fixed part of compression anchor and the effective reinforcement method for several types of soil were suggested. The following conclusions were made from this study : (1) A formula, which is able to calculate the grout strength in the fixed part of the compression anchor, is suggested. (2) The strength increment ratios( $R_{si}$) are 100％, 132％, 147％, 217％ according to the reinforcement method of grout. The reinforcement method is Non, Outside spiral, Inside-Outside spiral, Steel pipe, respectively. (3) The strength increment ratios( $R_{si}$) by reinforcing can be 8.23 times the strength increment effect according to the reinforcement types and ground confining pressure. (4) The steel pipe reinforcement is most effective in decomposed soil while, in the case of hard rock ground, high confining pressure is exerted on the grout, so there is no need to use reinforcements.

• 한국방재학회:학술대회논문집
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• 2007.02a
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• pp.37-40
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• 2007

Although masonry buildings fell into disfavour in the 1990's because of factors such ac bricklayers' high labor costs, bad reputation of poorly constructed masonry, masonry face wall is still preferred in korea as well as in other countries for its decorative value. Recently may problems with masonry face wall with opening have been reported, including cracks, deflection, swelling and even wall collapse in old masonry buildings, that mainly induced from the corrosion of connecting materials. So, it is necessary to develop the effective and uncorrosion connector. Therefore, this study aims to investigate the structural performance of masonry face walls with opening constructed by new connectors, spiral stainless anchors and to provide basic data for the field application of this method. The specimen reinforced bed joint has maximum load and displacement any other specimens.

• Explosives and Blasting
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• v.29 no.1
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• pp.10-16
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• 2011

To make large slopes or rock structures stable, supporting systems, such as anchor bolt, rock bolt and spiral bolt which are developed recently, are commonly used. In this study, in-situ pull-out tests were carried out to compare the characteristics of rock bolt that is most widely used with ones of spiral bolt that is newly developed. Re-pull-out test for the spiral bolt in which loading and unloading cycles are repeated three times showed that the maximum pull-out load is almost constant irrespective of the number of loading cycles, which may be due to no failure between spiral bolt and filler. On the other hand, the maximum pull-out load for the conventional rock bolt decreases with the number of loading cycles due to the partial failure between rock bolt and filler.

• Archives of Plastic Surgery
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• v.40 no.6
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• pp.773-778
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• 2013

Background In the management of mallet deformities, oblique retinacular ligament (ORL) reconstruction provides a mechanism for automatic distal interphalangeal (DIP) joint extension upon active proximal interphalangeal joint extension. The two variants of ORL reconstruction utilize either the lateral band or a free tendon graft. This study aims to compare these two surgical techniques and to assess any differences in functional outcome. As a secondary measure, the Mitek bone anchor and pull-in suture methods are compared. Methods A single-institutional retrospective review of ORL reconstruction was performed. The standard patient demographics, injury mechanism, type of ORL reconstruction, and pre/postoperative degree of extension lag were collected for the 27 cases identified. The cases were divided into lateral band (group A, n=15) and free tendon graft groups (group B, n=12). Group B was subdivided into the pull-in suture technique (B-I) and the Mitek bone anchor method (B-II). Results Overall, ORL reconstructions had improved the mean DIP extension lag by $10^{\circ}$ (P=0.027). Neither the reconstructive technique choice nor bone fixation method identified any statistically meaningful difference in functional outcome (P=0.51 and P=0.83, respectively). Soft-tissue injury was associated with $30.8^{\circ}$ of improvement in the extension lag. The most common complications were tendon adhesion and rupture. Conclusions The choice of the ORL reconstructive technique or the bone anchor method did not influence the primary functional outcome of extension lag in this study. Both lateral band and free tendon graft ORL reconstructions are valid treatment methods in the management of chronic mallet deformity.