Characterization of the shear wave velocity of soils is an integral component of various seismic analysis, including site classification, hazard analysis, site response analysis, and soil-structure interaction. Shear wave velocity at offshore sites of the coastal regions can be measured by the suspension logging method according to the economic applicability. The study presents some methods for estimating the shear wave velocity profiles in the absence of site-specific shear wave velocity data. By applying generalized regression neural network (GRNN) for the estimation of in-situ shear wave velocity, it shows good performances. Therefore, this estimation method is worthy of being recommended in the later engineering practice.

m-method is a widely used method for pile-soil interaction analysis. The main shortcoming of traditional m-method is ignoring the non-linear of soil. The actual relationship between the m and the displacement of pile (y) caused by loads is non-linear; however, it is unreasonable to used a linear curve and a fixed value of m during the calculation. Two methods for getting the m-y curve based on the p-y curve and the NL method are given. Linear spring is used and the m is dynamic modified based on the m-y curve by iteration. A test problem of a large-diameter monopile for offshore wind turbine is given and the dynamic modification of m of the full-range, the shallow and the deep-seated soil are carried out. It reveals that the dynamic modification of m by iteration made it possible to consider the non-linear of soil; the difference between the traditional m-method and the p-y curve method or NL method is caused by the way that using one and fixed m value and it is reasonable to use the non-linear m-y curve obtained by in-situ test; the lateral load-bearing capacity of the pile is influenced mainly by the soil between the mud-line and the depth of 3~5D (pile diameter), so that the dynamic modification of the m can be carried out for this part of soil to raise efficiency.

Architectures of fault systems play important role in stability and mechanics of rock mass. While growth mechanism of faults is intrinsic controler for architectures of fault systems. This paper presents a case on faulting in the dam area of an oversized hydropower in Southwestern China. The faults in this area are mostly strike-slip faults with shallow brittle deformation characters, extending tens to hundreds of meters. These faults can be divided into four groups which are formed during two generations corresponds to two periods of tectonic events. Growth model of these faults have been built based on geologic and mechanic data. The first generation of faults was formed based on preexisting joints. While the secondary generation emerge only if the existing faults become critically misaligned during rotation of the primary stresses. The criterion laws for formation of secondary faults are suggested. According to the growth model, we can predict placement of secondary faults in space. Conversely, when geometry and space characters of the fault systems are known, we can estimate mechanic parameters and tectonic environments of the rock mass.

Along with the increasing use of cables in power grid and the increasing ration of distributed power sources’ synchronization, such as small hydropower’s synchronization, increasing the reactive power transmission on the line, make it difficult to achieve the balance of reactive hierarchical partition. Take a certain region’s power grid for actual examples, after the installation of magnetic control reactor (MCR), using immune genetic algorithm (IGA) to coordinate the capacity of magnetic control reactor and the existing reactive power resources, the results show that the magnetic control reactor does much good to absorb the system’s excessive reactive power and limit the voltage’s increasing.

Calcareous sand is a special marine geotechnical medium that exhibits interesting physical and mechanical properties resulting from its composition and structure. In the current paper, the blasting compression wave (P-wave) attenuation mechanism of calcareous sand under explosion was studied through explosion experiments. The decay law of the P-wave was obtained based on the earth pressure at different distances from the blast center. The results show that, the broken, compress, and damage zones were formed under the effect of blasting load, many particles were broken near the blasting zone. Calcareous sand exhibits strong absorption and attenuation effects on the P-wave because of its particle breakage characteristics.