Study on mechanical performance of super long cast-in-place piles in construction phase based on distributed fiber optic sensors
LIN Guoqi1,2,3, HONG Chengyu1,2,3*, RAO Wei1,2,3
1. College of Civil and Transportation Engineering, Shenzhen University, Shenzhen 518060, Guangdong, China; 2. State Key Laboratory of Intelligent Geotechnics and Tunnelling, Shenzhen 518060, Guangdong, China; 3. Key Laboratory of Coastal Urban Resilience Infrastructure, Ministry of Education, Shenzhen 518060, Guangdong, China
Abstract In order to study the long-term stress characteristics of super-long cast-in piles, taking the construction Project of the second building in the North District of a Talent apartment in Shenzhen as the research background, the long-term monitoring of piles for nearly two years was monitored based on distributed optical fiber sensing technology. The strain transfer coefficient of the armored distributed optical fiber sensor was studied by laboratory tests; Combined with the hyperbolic model of the pile-soil interface, the long-term load variation law of super-long and large-diameter cast-in-place piles was revealed. The results showed that the strain transfer coefficient of the armored fiber was about 0.668 and did not depend on the load and time. The superlong and large-diameter cast-in-place pile mainly bore the upper load by the middle and upper part of the pile body. The axial force and lateral friction of pile body increased positively with the number of completed floors. When the construction was completed, the transfer coefficient of pile side friction resistance was about 52.64%, and the surface pile was in a safe state in terms of bearing capacity.
LIN Guoqi,HONG Chengyu,RAO Wei. Study on mechanical performance of super long cast-in-place piles in construction phase based on distributed fiber optic sensors[J]. Hazard Control in Tunnelling and Underground Engineering,
2023, 5(4): 65-71.
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