• Journal of the Korean Geotechnical Society
• /
• v.33 no.2
• /
• pp.27-34
• /
• 2017

Various earth retaining wall methods were used on the domestic construction sites and a cast in place pile (C.I.P) method was mostly applied at deep excavation. Because of a lot of shortcomings in the C.I.P method, a new method using PHC-W earth retaining wall was developed. The earth retaining wall method using PHC-W piles has a lot of advantages including that it is safer than other earth retaining wall methods due to uniform quality and high rigidity. PHC-W was designed to effectively resist lateral earth pressure by alternating cross section of PHC pile. And increment of bending moment and shear strength were verified through KS F 4306 tests, and were increased by 42% and 98% more than KS standards.

• Journal of the Korean Geotechnical Society
• /
• v.33 no.12
• /
• pp.115-125
• /
• 2017

PHC-W earth retaining wall could be constructed continuously. Various retaining wall methods such as C.I.P. etc. method require separate waterproof method. However, the PHC-W retaining wall method prevents leakage of groundwater by inserting a waterproofing material at connection part between 2 PHC piles. In this study, the experimental study on 3 waterproofing method for PHC-W retaining wall was conducted at the model pressure chamber. In the method using textile with 1-liquid type and 2-liquid type urethane, rapid leak occurred at the pressure of 120 kPa and 140 kPa or more. In the method of textile with grouting, rapid leak occurred at the pressure of 120 kPa or more, however, in this method, the rapid leakage happened at the top part and the bottom part reinforced with urethane.

• Journal of the Korean Geotechnical Society
• /
• v.35 no.3
• /
• pp.5-16
• /
• 2019

With the recent concentration of urban populations, the constructions of large structures are increasing, along with the development of foundations for large structures. PHC Piles have been used in many structures ever since Japanese introduced the technology at the end of the 20th century. Recently, many studies on the use of the PHC Pile have been carried out as earth retaining using the merits of PHC piles. In this study, static axial compression tests were conducted on the PHC-W piles constructed as column-type in building underground additional wall using the PHC-W earth retaining wall. The end bearing capacity of pile was calculated using the axial load transfer measurement that was obtained from the static axial compression test result. Since end bearing capacity of the PHC-W pile embedded in weathered rock showed a different behaviour from the conventional PHC pile, the calculation method of end bearing capacity for column-type PHC-W piles would be proposed. The unit ultimate end bearing equation proposed for single and group PHC-W pile embedded in weathered rock is $q_b=13.3N_b$ and $q_b=6.8N_b$.