말뚝두부 유압잭 양방향 재하시험

영신컨설턴트 (02) 529 8803 ystcha@naver.com 2021 12

 

 

기존의 양방향 재하시험은 시험 종료 후 유압잭을 회수하지 못합니다.

 

말뚝 두부 양방향 재하시험은 유압잭을 재사용할 수 있어 비용을 절감할 수 있습니다.

 

conventional bi-directional load test has been well documented by Osterberg (1995, 1998), Schmertman et. al., (1998), and numerous others. The test method requirements are further delineated in ASTM D8169/D8169M-18, Standard Test Methods for Deep Foundations Under Bi-Directional Static Axial Compressive Load. The main advantage of the conventional bi-directional test is the ability to test up to twice the jack assembly capacity since the embedded jack pushes in both directions from its embedded location. The main disadvantage of the test is that the jack assembly is embedded and is therefore not retrievable.

 

 

기존 선단 유압잭 재하 양방향 재하시험 Bi-Directional Load Test (BDLT)

 

 

말뚝두부 유압잭 양방향 재하시험 Top-Loaded Bi-Directional Test (TLBT)

 

                  선단 유압잭 재하                                 말뚝두부 유압잭 양방향 재하시험  

 

 

선단과 말뚝두부 유압잭 양방향재하시험

 

선단 유압잭 양방향재하 시험

 

  SQUID Results for BDLT Shaft. 선단 지지력, 선단 유압잭 재하

 

말뚝두부 유압잭 양방향 재하 시험

 

SQUID Results for TLBT Shaft. 선단 지지력 말뚝두부 유압잭 재하

 

 

말뚝 형상 수화열 건전도 시험 말뚝 형상

유압잭 선단

유압잭 말뚝두부

 

 

하중전이 유압잭 선단                                     하중전이 유압잭 말뚝두부

 

등가 곡선 Equivalent Top Loading Curves

Osterberg (1995) proposed that an equivalent top loading (“ETL”) curve could be developed by adding the loads mobilized by the upward and downward bearing plates at equal plate movement. The elastic compression of the foundation was considered negligible in this procedure which is referred to as the original ETL method.

The differences in the maximum ETL loads are due to the bearing plate loads reached at a given displacement. When significant differences occur between bearing plate load-displacement behavior, the maximum ETL load relative to the maximum test load is reduced.

 

Equivalent Top Loading Curves Results Using Modified Method