Ohkozu old movable weir of the Shinano River at Nagaoka city in Niigata Prefecture was demolished due to antiquated equipment in accordance with the construction of a new movable weir. Based on the results of boring exploration conducted during the construction, continuous cavity below the old movable weir was observed. Its continuous cavity is present over the entire area of the movable weir. The cavity of up to 16 cm has been confirmed. The following reason have been considered as the cause; 1) erosion by river water seepage flow due to big water head difference, 2) settlement of the surrounding ground due to liquefaction. Even if the pile foundation supporting the weir is robust after an earthquake, the bearing capacity of pile foundation is reduced by the liquefaction-induced ground settlement and the weir structure becomes unstable. Accordingly, risk of accelerating the erosion by the river water seepage flow is also increased. In this research, the cavity generating mechanism due to the liquefaction-induced ground settlement is focused on. First, 1-G shaking table model tests are conducted to clarify the influence of the presence of pile and weir column, number of piles to deformation and liquefaction of the surrounding ground.

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The old movable weir at Shinano River Ohkouzu in Nagaoka city was demolished owing to aging of structure, after construction of the new movable weir. This study reports the rapid loading test results of wooden piles installed below the foundation of movable weir and discusses the design method of foundation. Ground survey clearly illustrated the geological structure of the ground and indicated the wooden piles of 13m in length below the pillar was supported by the dense sandy layer. On the other hand, the wooden piles of 7m in length at the channel was shown to be supported by the thin dense sandy layer. Ultimate bearing capacity of wooden pile was estimated by the in-situ rapid loading test of piles. It matched with the design value in case of the channel, but it was smaller than that in case of the pillar. The foundation design of the pillar was found based on the piled raft foundation theory. Wooden piles had maintained the integrity of material, although it was constructed before about 80 years.

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High capacity jack-in piles with working load of up to 3000 kN were successfully designed and constructed for a proposed residential apartment of up to 24-storey high in East Ledang, Nusajaya, Johor, Malaysia. The installation of jack-in pile was carried out after preboring works to ensure a minimum pile length of 5.0 m below cut-off level due to the shallow hard layer (SPT-N > 50) of the weathered sedimentary rock formation. The prebored hole was backfilled with loose soil and jack-in spun pile was installed with termination criteria of minimum two (2) times working load, with the maximum jack-in pressure maintained for at least 20 seconds and the procedure repeated three (3) times for each pile. The termination criteria includes pile head settlement not exceeding 2.0 mm for each pile set / termination reading and the set readings were taken at least three (3) times with an interval of not less than three (3) minutes between each set. The above procedure was adopted to minimize the effect of excess pore-water pressure which may cause premature termination of the pile. The performance of the jack-in pile system was validated based on results of pile static load tests and instrumented test pile. The obtained load test results are discussed in this paper.

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Sonar Roughness Profiling System (SRPS) that can be used in the construction site was developed and verification tests were conducted to evaluate the applicability of SRPS. Firstly, in the indoor test, objective was to study the ability of sonar sensors. It was tested to check the effect of different shapes and turbidity using five specimens. It was found that the sensors had an accuracy of 1 mm. Plus, it was not greatly affected by the change of the shapes and turbidity. Secondly, in order to confirm field application of SRPS, tests were carried out on site. Although some problems were found, test was completed properly according to test procedure. Based on the test results, it was confirmed that SRPS could be used to measure socket roughness on site where shaft were drilled in rock.

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A field investigation reported progressively severe scour around a bridge river-crossing PC bridge in southern Taiwan after a series of typhoons and storms. Layout misalignment was found on caissons up to 1.7 m from their designate positions. A retrofit project was executed with concrete to integrate substructures and caissons as one structural element. Unfortunately, embedded caissons were exposed their upper portion on 6 piers in different severities. Failure retrofitting developed as structural discontinuities on 3 piers. Such a deficiency could impinge on the toppling issue of superstructure in case of occurrence of critical flooding or earthquake. A substructural stability analysis indicated its structural stability lying on the unsafe side on the most severe structural detrimental pier for the pier bottom was partially attached atop a caisson without any protection or repair. Finally, temporary substructural retrofitting was suggested to improve the weak linking between pier and caisson.

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Wind power engineering is the most dynamically developing type of renewable energy sources. Having studied the energy potential of wind in Kazakhstan, the Government of the Republic of Kazakhstan in association with the Development Program of the United Nations Organization "Kazakhstan - Initiative of the Development of Wind Power Engineering Market" defined Ereymentau district of Akmola region as the most future-oriented place for the construction of wind power plants. This article reveals the technical and economic comparing of types of foundations of wind power unit (WPU) in hydrogeological conditions of Ereymentau district.

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A series of full-scale in-situ pull-out tests has been carried out for cast-in-place concrete piles with one-belled or two-belled enlargements in order to investigate the characteristics of uplift resistance behavior of the piles with belled enlargements. In-situ pull-out tests for six belled piles and five multi-belled piles were performed at ten sites. The test piles were designed using steel-reinforced concrete structures to be able to reliably transfer the tensile force. A long H-section structural steel beam was inserted onto the pile toe with stud connectors arranged over the length of the H-section. All test piles were installed strain gauges at several sections along their depth to estimate the axial force. The results indicated that larger peripheral surface resisting stresses were exhibited by belled enlargements compared with the shafts embedded in almost identical soil layers. According to the test results, a design formula for estimating the peripheral surface resisting stress of the belled enlargement based on soil strength was shown.

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