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Because thin plate reinforced concrete members such as walls and slabs are greatly influenced by the drying shrinkage, cracks can occur in these members due to the restraint of the volume change caused by drying shrinkage. Therefore, the control of cracking due to drying shrinkage is very important in building construction that the thin plate members are frequently used. However, few researches of estimating shrinkage cracking in RC walls have been executed, and the cracking control design of RC walls has been conducted based on the experience rather than the quantitative design method. In this study, the practical cracking prediction method using equivalent bond-loss length Lb was proposed for the quantitative drying shrinkage crack control of RC wall. The calculated values using proposed method were compared with the experimental results from uniaxial restrained shrinkage cracking specimens and the investigative values from the field study. In general, the results of this method were close to those of the experiment and the field study.

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Pile penetration and rebound amount measurements during pile driving are important in analysis of penetration and bearing characteristics of piles and for assurance of pile installation quality. Traditional manual measurement of penetration and rebound of piles exposes engineers under unfavorable environment of injury risk and significant vibration and noise. To improve accuracy of pile penetration and rebound measurements and to ensure safety of engineers during pile driving, the close-range photogrammetry approach was implemented. For the track of three-dimensional spatial information of one point on the pile during driving, a series of stereo pair images of the point attached on a pile is required using more than two camera systems at different locations. In this study, two charge coupled device cameras were used to obtain stereo images. Robust measurements and reliable results can be guaranteed by the constrained geometry of close-range photogrammetry. From the field implementation, it was found that the newly developed pile penetration and rebound measurement system is accurate and safe.