To minimize the damages of pile foundation resulted by large ground deformation during earthquakes, a pile with energy dissipating device, High Ductility Pile (HDP) or High Ductility Aseismic Jointed (HDAJ) spliced pile, was newly developed in Japan. In this study, the bending characteristics of HDP were investigated via a series of bending and cyclic loading experiments. The analytical model of HDP was then established accordingly. The results either from actual experiments or numerical analyses show that the HDP has the same moment-resistant capacity as the conventional piles, but has much better ductility. Therefore, the HDP might be a good solution for the seismic design of pile foundation.
In the field of pile foundation, no matter in the establishment and application of code, design philosophy and construction technique, the developments between Taiwan and China exist many differences. This paper firstly presents the major pile types and applications for construction in China. Moreover, a comprehensive study on comparison of design principle, methodology, requirement and the evaluation of pile capacity between the design codes of Taiwan and China are then expanded. Finally, some case studies of pile foundation applied to petrochemical plant are introduced to demonstrate the design and construction of pile foundation in China.
To design bearing capacity of single pile on slopes mainly depends on surrounding stratum’s allowable lateral resisting capacity, not material strength of pile. Lateral bearing capacity of single pile is composed of pile stiffness and horizontal subgrade reaction provided by adjacent stratum, and the deformed curve can be derived from elastic beam theory. When pile stands on slopes, the coefficient of horizontal subgrade reaction and ultimate horizontal resistance will be thus reduced. For the topic of lateral resistance of short pile on slopes, this paper introduces LTBASE program that developed by Prof. Borden in North Carolina State University, and Japan Road Association program. According to the comparision of actual cases analysis and test results in the field, these two methods can obtain reasonable predictions and can provide a good alternative for engineers to predict the lateral resistance of single pile on slopes.
STATNAMIC Loading Testing Technology was invented in 1987. Cumulatively, the number of total STATNAMIC tests performed in the world is more than 1000. STATNAMIC Loading Test was introduced to Taiwan in 1999 and 36 tests have been performed in Taiwan. To verify the bearing capacity of large diameter bored pile, STATNAMIC Loading Test method overcomes the difficulties of Dynamic Load Testing. Since no stress wave phenomena is occurred in the STN, the test results are close to the behavior of Static Load Test. This paper presents three case histories of bored pile and the test results are compared with those of Static Load Test.
Due to the behavior of gravel formations are significantly different from those of alluvial. The reliable SPT N test results are still limited. Hence, the simplify formulas of SPT N value used to analyze bearing capacity of pile are not available on gravel formations. This paper presents the load transfer characteristics of fully instrumented all casing bored pile of 1.5 m in diameter and seated about 12 m to 15 m below the testing ground level. In this paper, 3 sets of test pile (TP-1~TP-3)are carried out downward static load test and 2 sets of test pile (TP-4~TP-5) are performed uplift test. None ground water level are observed on site for each test pile. Both of loading test types are setup reinforcing bar stress transducer and extensometers at proper depth of level to monitor the axial force of pile and shaft movement. From the test results, particularly load transfer characteristics, mobilized shaft skin friction and shaft movement were compared with those of all casing bored pile. And also, the β-method used for the evaluation of pile capacity and the reliable relationship between the maximum downward and uplift shaft friction are all studied for their reference.
This paper presents a difficult case on application of Tangent Piled Wall (TPW) to stabilize the volcanic strata with boulders in the expansion project of existing plant in Philippines. A comprehensive introduction containing site investigation, construction methods and design concept, troubleshooting during construction and integrity tests and safety monitoring, is highlighted in this paper.
This paper looks into the problem of settlement of pile-supported structures regarding its causes， mechanism and preventive measures. The settlement of piles is closely related to the position of soft and compressible soil， displacement relative to piles， pile-soil interaction behavior； also influenced by the weight， height ， basement depth and the surcharging effect of large group of structures， and other factors such as excessive pumping of ground water， surcharge loads due to extensive areal fill or stock piling of materials. Most of these adverse effects may be avoided by the use of large diameter deep piles embedded in strong bearing stratum and constructed according to the improved methods.
The total tunnels length of the New Wuchieh Tunnel & Lishi Creek Diversion Project, Taiwan Power Company, is about 16.5 km. Two major geologic structures exist in the project area; they are the Lishan fault and the Dili fault. Due to the existence of the Lishan fault is still a doubt to the geologic field of Taiwan. The name, Lishan structure rather than Lishan fault, is used in the design stage of this project. The designers predict that the geologic condition might be fractured and sheared rock with high-pressure groundwater. During the excavation stage, the poor geologic zone was encountered at the location inferred as designed. It is actually not a fault but a shear zone with no groundwater. This literature briefly introduces the actual geologic condition of the Lishan structure from the viewpoint of tunnel excavation of this project. The geologic field will still study the issue of the existence of the Lishan fault outside the project area.