Fish Anchor Dived – Confirmation Through Field Tests in the Swan River

This paper reports the results from field tests on a 1/15th scale recently developed fish anchor. The tests were conducted at three locations in the Swan River, Perth. Two series of tests were performed from the Burswood and Maylands jetties with water depths between 1.1 and 1.9 m. The final series of tests were undertaken in deeper waters of 2.6 m from a barge. The riverbed at the Burswood Jetty and barge test location consisted of soft clay, and that at the Maylands Jetty comprised sandy silt. The tip embedment depths of the scaled fish anchor, with dry weight of 0.304 kN and impact velocity of 5.89∼9.55 m/s, in soft clay were 1.17∼2.40 times the anchor length. For similar impact velocities, the tip embedment depths in sandy silt were 30 ∼ 60% shallower than those in soft clay. By comparing the field test data in clay, the fish anchor achieved normalised embedment depths similar to those of the torpedo and OMNI-Max anchors under half or less impact velocity. Most importantly, the field tests confirmed the diving behaviour of the fish anchor under loading with mudline inclination of 20° and 25°, with the second peak dictated the capacity. The ultimate capacity was 5∼7 times the anchor submerged weight in water.

Finite difference analysis of prefabricated vertical drains assisted with surcharge preloading of Hiep Phuoc soft clay in Vietnam

A series of finite difference analysis of the soft ground treatment with PVDs application has been performed with the application of the newly developed consolidation model. The model utilizes the concept of multi-compression indices and coefficients of consolidation to investigate the behaviors of the soft ground deposit on pore water pressure dissipation, surface and sub-layered ground settlement and to validate the newly developed CONSOPRO finite-difference procedure. Furthermore, the pre-consolidation pressures of the soft ground deposit are characterized with the combination of the piezocone penetration profiling and constant rate of strain consolidation tests under 0.02 %/min. on undisturbed samples which were retrieved at the investigated site, Saigon Premier Container Terminal (SPCT) in the South of Vietnam. On the comparison of the back-calculation results to the field observing data, the correlation between the coefficients of consolidation determined by constant-rate-of-strain (CRS) consolidation tests and those from piezocone dissipation tests, which were carried out after the soil improvement, is developed.