Skin friction behavior of pile fully embedded in limestone
- PDF / 2,166,189 Bytes
- 7 Pages / 595.276 x 790.866 pts Page_size
- 10 Downloads / 200 Views
ORIGINAL PAPER
Skin friction behavior of pile fully embedded in limestone Abdulhafiz Alshenawy 1 & Wagdi Hamid 1 & Ahmed Alnuaim 1 Received: 5 October 2017 / Accepted: 3 January 2018 # Saudi Society for Geosciences 2018
Abstract Pile foundation system in limestone rock layers is commonly used in Riyadh area, Saudi Arabia, for high-rise building, bridges, and other structures. Especially in Riyadh region, bored piles are used for bridges and underpasses not only because of bearing capacity but mainly because of limited spaces for using shallow foundations. In addition, piles are used for bridges over wadis to avoid scouring effects. The loads are transferred by the pile from a superstructure to the rock strata through side friction and endbearing resistance. However, there are no studies conducted in Riyadh area to quantify the skin friction capacity of pile embedded in limestone rock. Accordingly, this experimental study describes in details the behavior of load transfer mechanism through side friction only on a reinforced concrete pile (75 mm diameter and 150 mm long) constructed on hard limestone rock sample. Soft material (Styrofoam) was placed at the bottom of the pile to eliminate the effect of end-bearing resistance. Unconfined compression test was conducted on intact rock sample to find out the properties of the rock used. The result of the ultimate side friction obtained from the test was compared with values predicted by other researcher methods mentioned in the literature. Keywords Limestone rock . Pile . Side friction . Pile load test . Unconfined compression test
Introduction Rock-socketed or embedded piles derive their load carrying capacity from two components’shearing resistance at the concreterock interface around the cylindrical surface of the pile and endbearing resistance atthe pile tip. There are no studies conducted in Riyadh area to quantify the skin friction capacity of pile embedded in limestone rock. This paper describes the behavior of axially loaded piles fully embedded into limestone rock by applying pile load test conducted in the laboratory. Also, a compression test was conducted to find out the properties of the rock such as unconfined compressive strength, Young’s modulus, and Poisson’s ratio. Most of the pile load tests conducted by the researchers were carried out in sedimentary rocks having lower strength than typical rock types encountered in different places in the world (Bisht et al. 2013). Many researchers suggested that the ultimate side friction related to the unconfined compressive strength of the rock qu,
and an empirical constant usually noted α which assumes a linear function such as: (Reynolds and Kaderabek 1980): f max ¼ 0:3qu
ð1Þ
(Gupton and Logan 1984): f max ¼ 0:2qu
ð2Þ
(Reese and O’Neill 1988): f max ¼ 0:15qu For rock with qu up to 1:9MPa
ð3Þ
(Toh et al. 1989):
* Abdulhafiz Alshenawy [email protected] 1
Department of Civil Engineering, King Saud University, Riyadh 11421, Saudi Arabia
f max ¼ 0:25qu
ð4Þ
Other researchers like Williams et al. (1980) a
Data Loading...
