Conference site

　　Guests experiencing instruments on site

　　Li Xia: Differences between High-Strain Dynamic Testing and Static Load Test

　　Manager Li Xia from the Foundation Pile Testing Department of EPC shared two thematic reports with attendees: "Introduction to Precast Pile Driving Process Simulation and Pile Driving Monitoring Technology" and "Quality Assurance and Testing Technology Analysis for Bored Piles." In the reports, Manager Li detailed methods for pile integrity control and assurance and verification methods for bearing capacity, and introduced the analysis of CAPWAP and static load test results to help the audience understand and master the principles and value of high-strain dynamic testing.

　　Manager Li Xia presenting the thematic report

　　Manager Li Xia answering questions on site

　　Manager Li Xia answering questions on site

　　Zhang Jiansheng: High-Strain Method is Reliable, Saving Over 1 Billion Yuan in Testing Costs in 20 Years

　　Director Zhang Jiansheng from the Construction Engineering Quality and Safety Supervision and Testing Center of Shunde District, Foshan City, shared a report titled "Research Report on Water Softening of Bearing Strata for Prestressed Pipe Piles in Shunde Area." Currently, more than 80% of the bearing strata for prestressed pipe piles in Shunde are strongly weathered granite gneiss and mudstone, and many survey reports hastily classify such rocks as "easily softened by water." According to relevant regulations, pipe piles with such rock layers as bearing strata require static load tests for acceptance testing. But in reality, is static load testing appropriate or is high-strain testing more suitable?

　　Director Zhang of the Shunde Quality Inspection Station summarized at the meeting: "Our center has been conducting high-strain testing of foundation piles in the Shunde area for nearly 20 years, testing more than 100,000 piles for construction sites in Shunde. Compared with the traditional static load test method, it has saved construction units over 1 billion yuan in testing costs, and has also detected various quality hazards (such as 'short pile incidents'), making significant contributions to ensuring construction safety in the Shunde area."

　　Director Zhang giving the keynote speech

　　Director Zhang answering audience questions

　　Feng Guanghua: Risks in Overseas Pile Driving Projects, High-Strain Method Provides Protection

　　Director Feng Guanghua from the Foundation Pile Testing Department of CCCC Fourth Harbor Engineering Institute Co., Ltd. shared a thematic report with attendees on "Analysis of Steel Casing Edge Rolling Problems in Rock-Socketed Cast-in-Place Piles in an East African Project." An East African project is located on the west coast of Africa, with a high-pile wharf structure, a main body length of 435 meters, an approach bridge length of 776 meters, and an onshore passage length of 550 meters. The pile foundation adopts rock-socketed cast-in-place piles, and the steel casing is driven to the design elevation using a BSP-CG 240 hydraulic hammer. An SP120 pipe-end air-lift reverse circulation drill drills rock to 8m below the bottom of the steel casing, and after hole cleaning, concrete is poured. The concrete strength grade for the cast-in-place pile body is required to be C40. The steel casing is tested using high-strain testing, and the rock-socketed piles are tested using self-balanced static load testing (maximum test load 33000kN).

　　Through high-strain pile driving monitoring, it was found that the insufficient wall thickness of the steel pipe pile was the direct factor causing the edge rolling phenomenon, and the stress concentration zone at the thickened pile tip area was the weakest position during pile sinking.

　　Director Feng giving the keynote speech

　　After the meeting, attendees took a group photo, and the conference concluded successfully with applause and thanks from the participants.

　　This seminar is the second stop of the 2016 EPC PDI Technology Seminar. The next stop will be held in Hangzhou on July 26. You are welcome to attend. Follow EPC WeChat for the latest updates.