• Computers and Concrete
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• v.4 no.5
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• pp.363-376
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• 2007

The paper presents the development of an adaptable strut-and-tie model that can be applied to the design or analysis of four-pile caps that support axial compression and biaxial flexure from a supported rectangular column. Due to an absence of relevant test data, the model is validated using nonlinear finite element analyses (NLFEA). The results indicate that the use of the proposed model would lead to safe and economical designs. The proposed model can be easily extended to any number of piles, providing a rational procedure for the design of wide range of pile caps.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.41 no.1
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• pp.39-48
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• 2021

In this paper, an analytical model is proposed for assessing the natural frequency of barrettes subjected to vertical loading. The differential equation governing the free vibration of rectangular friction piles embedded in inhomogeneous soil is derived. The governing equation is numerically integrated by Runge-Kutta technique and the eigenvalue of natural frequency is computed by Regula-Falsi method. The numerical solutions for the natural frequency of barrettes compare well with those obtained from finite element analysis. Illustrated examples show that the natural frequencies increase with an increase of the cross-sectional aspect ratio, the friction resistance ratio and the soil stiffness ratio, and decrease with an increase of the friction aspect ratio, the slenderness ratio and the load factor, respectively.

• Korean Journal of Heritage: History & Science
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• v.51 no.4
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• pp.84-107
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• 2018

Cheommojik is a pile cloth, a type of textile whose surface is covered with short piles. The term chaedam was used during the late Joseon dynasty to refer to pile cloth rugs, while the terms yoongjeon, dantong and yangtanja were used in the early twentieth century. Various documents, newspaper articles and photographs confirm that pile cloth rugs were used by the general public as well as the royal family from the late Joseon dynasty onward, and that there were domestic manufacturers of such rugs at that time. This study investigated six pile cloth rugs that were produced after the late Joseon dynasty, five of which feature Persian knots made of cut pile, the other being made with the loop pile method. The cut pile rugs are rectangular in shape and measure between 72-98cm by 150-156cm; and they are decorated in the middle with patterns of butterfly, deer, and tiger or the ten longevity symbols, and along the edges with patterns composed of 卍 symbols. The ground warp of all six rugs are made from cotton yarn, while the ground weft is made of cotton yarn on three pieces, wool on one piece and cotton and viscose rayon. The ground weft yarn from four pieces are Z-twist yarn made with two or more S-twist cotton yarn. Four to six colors were used for the pile weft, all being natural colors except for red. Two or more S- or Z-twist yarn were twisted together in the opposite twist for the pile weft, with the thickness determining the number of threads used. Six or more weft threads were used to make the start and end points of the rug; and the ground warp ends were arranged by tying every four of them together. For the left and right edges, three or more threads were wrapped together into a round stick-like form, and the second and third inner ground warps from the edges were stitched on to the wrapped edge. For the loop pile, loops were made in the direction of the warp; the ground warp and the ground weft may have been made with cotton, the pile warp with wool yarn. An analysis of the components of three rugs was conducted to determine which types of animal hair were used for the pile weft. Despite some inconclusive results, it was revealed that goat hair and fat-tailed sheep hair were used, raising the possibility that various kinds of animal fur were used in the production of pile cloth rugs. The six rugs examined in this study are estimated to have been made between the late 1800s and the early 1900s. Although the manufacturer of the rugs cannot be confirmed, we concluded that the rugs were produced in Korea after referring to the documentation of the domestic production of pile cloth rugs during the aforementioned period and the form and placements of the patterns on the rugs.