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In this paper, the disadvantage of the conventional monitoring technology for offshore construction foundation is analyzed, that is, the real-time accurate monitoring data cannot be acquired during the period of extreme weather, so the risk assessment of foundation state cannot be presented in time. A new type of automatic monitoring technology is studied in detail in this paper. This technology can realize automatic data acquision and wireless data transmission, which can not be affected by external climate, and it can realize real-time monitoring and information monitoring. It has been applied in soft ground monitoring projects successfully with good social and economic benefits, which can provide some reference for similar projects. [ABSTRACT FROM AUTHOR]

In the theory of Mononobc and Okabe, the distribution of unit seismic earth pressure is linear and the location of application point of total seismic earth pressure is at H/3 from the base of retaining wall, which is different from test results. Based on the assumption of planar sliding surface in Coulomb's earth pressure theory and the moment equilibrium of sliding soil behind retaining wall, the seismic amplification factor is introduced, the method determining the application point of total seismic earth pressure is presented, the effective formula of unit seismic earth pressure is proposed and the effects of seismic amplification factor on seismic earth pressure and its distribution are analyzed. The results show that the total seismic earth pressure without seismic amplification factor is identical with those from Mononobc theory, which indicates that the latter is a special case of the proposed method; the location of application point of total seismic earth pressure is at 0.40H~0.50H from the base of retaining wall, which is identical with Sherif s experiments and proves that the proposed method is a further supplement of Mononobe's theory; the distribution of unit seismic earth pressure along the wall is non-linear and approaches to a parabola, and the maximum value is not at the base, which shall be paid attention during the stability design of retaining wall. [ABSTRACT FROM AUTHOR]

To better understand the application of multibeam echosounding (MBES) system in channel dredging, we determined the processes affecting error and data quality and clarified standard methods of multibeam parameter selection under different conditions. Accurate bathymetric data can be used to interpret geological processes and calculate the volume of materials added to or moved from the channel bottom. MBES can also be used to investigate bottom sediment coverage and to design the dredging plan in the pre-construction process. The MBES provides real-time accurate water depth for monitoring the dredging process and guiding the engineering schedule. By measuring the water depth of a dredged channel and comparing it with the design depth we can determine whether the engineering design requirements and technical specifications have been meet. Furthermore, the use of MBES has many advantages in channel dredging. It can play an important role in the dredging engineering design and is a good tool for inspecting dredging results, providing a reference for future related work. [ABSTRACT FROM AUTHOR]

Based on generalized Biot's dynamic consolidation theory and random wave theory, a FEM model for simulating seabed-pipeline interaction is established. The difference of excess pore pressure and vertical effective stress along seabed depth, and also internal stress of pipeline and excess pore pressure along the surface of pipeline under random and representative waves are analyzed, with emphasizing on the influence of the contact between the pile and soil and inertial effects on the dynamic response of pipeline under random wave, and carrying out the numerical simulation about the influence of burial depth, pipe diameter and the permeability coefficient of seabed on the pore pressure around pipeline and vertical displacement and internal stresses of pipeline. Numerical results conclude that soil-pipeline contact effect significantly affects the dynamic response of pipeline, but the inertial effect is not obvious. Neglecting the stochastic feature of wave will remarkably underestimate the dynamic response of pipeline. [ABSTRACT FROM AUTHOR]

The article discusses research which provided a mathematical model for the anchor impact on submarine pipeline on the basis of failure probability. Topics discussed include the annual failure frequency ranking to compare the frequency and risk of any of the relevant hazards, probability of hitting pipeline per anchor drop and probability of anchor dropping in target hitting zone.

The article discusses research which analyzed the dynamic response of submarine pipeline under seismic loading in earthquake prone area. Topics discussed include the three dimensional model of pipe-soil interaction based on linear elastic theory in hemi-indefinite space, modeling of pipe-soil interaction and selection and input of seismic wave.