Underwater explosive ram is adopted to treat the foundation in the project of petrochemical dock in Lanshan harbor. Feasibility of this kind of foundation reinforcement method in the project of petrochemical dock in L...Underwater explosive ram is adopted to treat the foundation in the project of petrochemical dock in Lanshan harbor. Feasibility of this kind of foundation reinforcement method in the project of petrochemical dock in Lanshan harbor is discussed based on the analysis and comparison of the difference of sea bottom elevation, physical and mechanical properties of sediments before and after explosive ram tests. The rational parameters of explosive ram are designed according to the result of the test. The quantitative data of underwater explosive ram are offered for large scale strengthening foundation of petrochemical dock in Lanshan harbor.展开更多
This paper presents in-situ seismic performance tests of a bridge before its demolition due to accumulated scouring problem. The tests were conducted on three single columns and one caisson-type foundation. The three ...This paper presents in-situ seismic performance tests of a bridge before its demolition due to accumulated scouring problem. The tests were conducted on three single columns and one caisson-type foundation. The three single columns were 1.8 m in diameter,reinforced by 30-D32 longitudinal reinforcements and laterally hooped by D16 reinforcements with spacing of 20 cm. The column height is 9.54 m,10.59 m and 10.37 m for Column P2,P3,and P4,respectively. Column P2 had no exposed foundation and was subjected to pseudo-dynamic tests with peak ground acceleration of 0.32 g first,followed by one cyclic loading test. Column P3 was the benchmark specimen with exposed length of 1.2 m on its foundation. The exposed length for Column P4 was excavated to 4 m,approximately 1/3 of the foundation length,to study the effect of the scouring problem to the column performance. Both Column P3 and Column P4 were subjected to cyclic loading tests. Based on the test results,due to the large dimension of the caisson foundation and the well graded gravel soil type that provided large lateral resistance,the seismic performance among the three columns had only minor differences. Lateral push tests were also conducted on the caisson foundation at Column P5. The caisson was 12 m long and had circular cross-sections whose diameters were 5 m in the upper portion and 4 m in the lower portion. An analytical model to simulate the test results was developed in the OpenSees platform. The analytical model comprised nonlinear flexural elements as well as nonlinear soil springs. The analytical results closely followed the experimental test results. A parametric study to predict the behavior of the bridge column with different ground motions and different levels of scouring on the foundation are also discussed.展开更多
In accordance with laboratory tests and theoretical analysis, the concept of unified equivalent harmonic wave loading is suggested and discussed in this paper. Such a concept may be more reasonable and widely applicab...In accordance with laboratory tests and theoretical analysis, the concept of unified equivalent harmonic wave loading is suggested and discussed in this paper. Such a concept may be more reasonable and widely applicable in offshore foundation engineering. A verification test has also been completed, in which the random wave loading and the corresponding unified equivalent loading were applied on soil samples. The test results show that the equivalent effect is satisfactory.展开更多
文摘Underwater explosive ram is adopted to treat the foundation in the project of petrochemical dock in Lanshan harbor. Feasibility of this kind of foundation reinforcement method in the project of petrochemical dock in Lanshan harbor is discussed based on the analysis and comparison of the difference of sea bottom elevation, physical and mechanical properties of sediments before and after explosive ram tests. The rational parameters of explosive ram are designed according to the result of the test. The quantitative data of underwater explosive ram are offered for large scale strengthening foundation of petrochemical dock in Lanshan harbor.
文摘This paper presents in-situ seismic performance tests of a bridge before its demolition due to accumulated scouring problem. The tests were conducted on three single columns and one caisson-type foundation. The three single columns were 1.8 m in diameter,reinforced by 30-D32 longitudinal reinforcements and laterally hooped by D16 reinforcements with spacing of 20 cm. The column height is 9.54 m,10.59 m and 10.37 m for Column P2,P3,and P4,respectively. Column P2 had no exposed foundation and was subjected to pseudo-dynamic tests with peak ground acceleration of 0.32 g first,followed by one cyclic loading test. Column P3 was the benchmark specimen with exposed length of 1.2 m on its foundation. The exposed length for Column P4 was excavated to 4 m,approximately 1/3 of the foundation length,to study the effect of the scouring problem to the column performance. Both Column P3 and Column P4 were subjected to cyclic loading tests. Based on the test results,due to the large dimension of the caisson foundation and the well graded gravel soil type that provided large lateral resistance,the seismic performance among the three columns had only minor differences. Lateral push tests were also conducted on the caisson foundation at Column P5. The caisson was 12 m long and had circular cross-sections whose diameters were 5 m in the upper portion and 4 m in the lower portion. An analytical model to simulate the test results was developed in the OpenSees platform. The analytical model comprised nonlinear flexural elements as well as nonlinear soil springs. The analytical results closely followed the experimental test results. A parametric study to predict the behavior of the bridge column with different ground motions and different levels of scouring on the foundation are also discussed.
文摘In accordance with laboratory tests and theoretical analysis, the concept of unified equivalent harmonic wave loading is suggested and discussed in this paper. Such a concept may be more reasonable and widely applicable in offshore foundation engineering. A verification test has also been completed, in which the random wave loading and the corresponding unified equivalent loading were applied on soil samples. The test results show that the equivalent effect is satisfactory.
