Static Pile Load Research Articles

Estimation of static jacking load (Pep) for the prestressed centrifugal concrete piles on some types of ground structure in Hai Duong city

Nowadays, the prestressed centrifugal concrete piles (PCCP) are applied in most major construction projects in Hai Duong city. The pile bearing capacity and static jacking load (Pep) are very important parameters for optimizing the pile foundation design, and they depend on the types of ground structure. The paper introduces the estimated method for the pile static jacking load which was applied for two types of ground structure in Hai Duong city (type I and type II). The results showed that the maximum static jacking load (Pepmax) was 66.6 tons and 76.6 tons at the depth of 32 m for types I and II, respectively. The results of evaluation and comparison between the calculated Pep with the actual Pep have provided the penetration coefficient (K) for each soil: K = 1.8 for fine sand; K = 1.5 for stiff sandy clay; K = 1.4 for firm sandy clay and K = 1.2 for soft soil.

Closure to “Pile Setup in Cohesive Soil. I: Experimental Investigation” by Kam W. Ng, Matthew Roling, Sherif S. AbdelSalam, Muhannad T. Suleiman, and Sri Sritharan

Closure to “Pile Setup in Cohesive Soil. I: Experimental Investigation” by Kam W. Ng, Matthew Roling, Sherif S. AbdelSalam, Muhannad T. Suleiman, and Sri Sritharan

Reduction Factor for the Unloading Point Method at Clay Soil Sites

Full-scale testing can be an integral component of quality control/quality assurance for projects involving construction of deep foundations. Rapid load tests are being used in the deep foundation industry as a method for assessing the axial static behavior of deep foundations. Since rapid load tests involve dynamics, inertial and damping forces must be considered in analyzing measured pile response to estimate the static pile response. The unloading point method (UPM) is typically used for this purpose. Generally considered a consequence of load rate effects in clays, results from the UPM must be further modified by a reduction factor to obtain a reasonable estimate of the static pile response. A reduction factor of 0.65 applied to the UPM for clay soil sites has been recommended by others. However, a review and analysis of readily available literature reporting static and rapid pile load test results at sites predominantly consisting of clay soils indicate that an average reduction factor of 0.47 is more appropriate. Rapid load testing should be used judiciously. When using the UPM to estimate static pile capacity from rapid load tests in clay, static load tests should be performed to validate the reduction factor used to interpret rapid load tests.

Load-settlement behaviour of socketed piles in sandstone

Nine Static vertical pile loading tests were carried out in Abu-Dhabi, the United Arab Emirates in order to assess the end bearing capacity and settlement of piles bored in slightly silty sands overlying soft rocky horizons like sandstone and calcarenite. The paper is aimed at presenting the results of interpretation of the pile tests in order to estimate the end bearing capacity in correlation with the unconfined compressive strength Rc and the rock quality designation (RQD). Load-settlement behaviour is also studied through an analysis by the elastic methods commonly used in pile design.