Abstract:This study summarizes the classification，research status，advantages and disadvantages of existing ocean wave forecasting methods. Through the comparative analysis，it can be noted that the three traditional wave forecasting methods，semiempirical and semitheoretical forecasting method，empirical statistical forecasting method and numerical forecasting method，are significantly regionalized，face the challenge of modeling difficulties，and require high realtime data. Meanwhile，this paper also analyzes the developing trends and prospects the application foreground of some new techniques such as big data，artificial intelligence，and deep learning in the field of wave forecasting.

Abstract:Abstract: Based on the measured tidal data in Hangzhou Bay，the spatiotemporal variations，causes and influencing factors of the annual maximum high tide levels in Hangzhou Bay were systematically analyzed. The results showed that the annual maximum high tide levels in Hangzhou Bay rose in a fluctuating manner，with a rising rate of 0.951.84 cm/a，the raise valuetop of the bay was larger than the middle of the bay and the middle of the bay was larger than the mouth of the bay. The annual maximum high tide levels occurred most frequently in August，followed by July，September and June. In the annual maximum high tide levels at Zhapu station，59% of them were affected by typhoon surge，and 95% of them were in spring tides. On the，contracted river for regulation in the Qiantang estuary caused the elevation of the high tide level of astronomical tide，on the other hand，it caused the increase of storm surge. In the past 30 years，the increase of typhoon intensity and adverse typhoon path for Hangzhou Bay also caused the increase of storm surge and the elevation of the annual maximum tide level iu Bay was exacerbated by rising mean sea level.

Abstract:In this paper，a onedimensional mathematical model is developed to study the sediment transportation law in the downstream reach of Sanshenggong Reservoir under different flow conditions and sediment concentrations. The sediment concentration，cumulative erosion and deposition，and erosion and deposition along the river section are counted，the erosion and deposition per length of the river is calculated，and the erosion and deposition characteristics of different river sections are quantitatively analyzed. The results show that under the same flow discharge，the larger the sediment concentration in entry，the larger the erosion and deposition along river and cumulative erosion and deposition. However，the sediment concentration after the 100 km downstream reach is prone to be consistent，having nothing to do with the entry sediment concentration. Meanwhile，the discharge flow and sediment content of the reservoir have a significant impact on the erosion and deposition of the downstream reach. When the sediment content of discharge is not more than 3kg/m3，the downstream river is dominated by erosion. Finally，the erosion and deposition change of the reach from the reservoir to the Sanhu Estuary are significantly affected by the upstream inflow and sediment conditions，and the balanced inflow and sediment coefficient of erosion and deposition is around 0.004kg·s/m6.

Abstract:Aiming at the problem of sewage pipeline leakage，the attenuation of soil strength parameters with the increase of saturation was simulated in ABAQUS platform with user defined USDFLD subroutine and the generalized soil strength formula. To evaluate the influence range of leakage on the ground surface，this paper analyzes the scope of saturated area by the leakage of sewage pipeline with different buried depths under the condition of the pipeline damage area change. Meanwhile, the variation of soil subsidence above pipelines and the stability of ground structure are also analyzed during 19 days after the leakage. The research results show that for the working condition with a buried depth of 1m，the influence range caused by leakage is the smallest，and the impact range caused by leakage is the largest when the buried depth is 2 m. If the substance is set to 30 mm as the threshold value of goound instability, the case with a buried depth of 1 m kept stable in the analysis time. With specified ground instability threshold values，the sewage pipelines with a depth of 25 m all experienced ground instability from deep to shallow in 15 to 19 days after the leakage occurred.

Abstract:Taking a geomembrane faced rockfill dam on thick overburden of a mediumsized reservoir as an example，the finite element method is adopted to carry out the threedimensional numerical simulation of seepage field of the dam and foundation，focusing on some influence factors，e.g.，different types，sizes and distributions of geomembrane defects. According to the calculation results of dam head distribution，seepage discharge and seepage gradient，the dam seepage safety is analyzed and evaluated. The results show that when the geomembrane has defects，it mainly affects the partial seepage field of the dam body and locally raises the phreatic line，but has little effect on the foundation and abutments. The seepage discharge through the dam body has also been greatly increased. The cushion layer behind the membrane near the defect plays an antiseepage role，and the corresponding local seepage gradient increases significantly. In general，the seepage prevention design can meet the requirements of normal operation of the dam.

Abstract:In this study，a series of triaxial creep tests of core asphalt concrete were conducted with the temperature controlled as 5℃，10℃，and 15℃，respectively，relying on an embankment dam with asphalt concrete core (ACED) located in the west of China. The test result indicates that a linear relationship is satisfied between the shear creep strain and time in the double logarithmic coordinates. The slope for the lines corresponding to the different deviator stress changes slightly，while exponentially decreases with the increase of the temperature. The shear creep strain at different time increases nonlinearly with the increase of the deviator stress，and this nonlinear behavior becomes more obvious with the increase of temperature. Moreover，with the increase of the temperature，the creep rate is accelerated，and the creep deformation is also increased. Larger creep deformation is observed under the action of larger deviator stress. The volumetric creep strain is greatly influenced by the value of deviator stress，which shows the compression in the low deviator stresses and the dilatancy in the large deviator stresses. Furthermore，the dilatancy is remarkably larger than the compression deformation. Besides，the influence of the confining stress on the creep of asphalt concrete core is also dependent on the value of deviator stress. The creep under different confining stress changes slightly in the low deviator stresses，while decreases with the increase of confining stress in the high deviator stresses.

Abstract:The effects of wave period，wave height and bubble diameter on the coating erosion were analyzed to study the mechanical erosion factors of the coating on the splash area of pier structure under the impact of low frequency reciprocating wave. Based on the ABAQUS/Standard analysis module，a threedimensional numerical model considering the wave period，wave height and bubble diameter is established to simulate the evolution process of bubble damage at the interface between structure and coating during the wave action. The results show that the relationship between the bubble strain and the influence range at the coating interface and the wave height is linear and positive，and basically independent of the wave period. However，the smaller the period，the faster the wave force acting on the coating interface and the maximum value is reached at half of the period. The strain and influence range increase with the increase of bubble diameter，while the smaller the bubble diameter，the more regular the strain distribution (elliptical shape). The higher the wave height，the shorter the period and the bigger the bubble diameter，the easier the bubble will break and the easier the coating of the pier structure will be stripped.

Abstract:To improve the rationality of the design method for reinforced concrete deep beams，a topological StrutandTie model method for multiobjective loads is proposed. On one hand，it is evolved from genetic evolutionary structural optimization algorithm and can be used to solve structures under multiobjective loads; on the other hand，it builds StrutandTie models according to the topological solutions，which links up the topology optimization and the engineering design. Two numerical examples of deep beams show the progress of[JP2]the project from establishment of initial design domain to evolution of topological solutions，and then to construction and analysis of StrutandTie model. Feasibility and stability of the new method are proved in these processes. From the points of view of constructing StrutandTie models and the corresponding mechanical properties of the models，the topological solutions of multiobjective optimization of loads are compared with those of singleobjective optimization of each load case，and their elastic superposition，and with those of singleobjective optimization of applying all load cases simultaneously as well. The results show the new method is more suitable for the mechanical properties of deep beam members and has better capability of global optimization. Multiobjective genetic evolutionary structural optimization of loads can effectively solve the ill conditioned load problem in multiobjective optimization. It can be used for establishing StrutandTie models intuitively，which provides important reference for the design of reinforced concrete deep beams.[JP]

Abstract:For the local scouring problem caused by the tidal current flow of piletype buildings such as bridge piers in the estuary area，the physical model is adopted in this study to reveal the mechanism process of local scouring of piers caused by tidal currents and the morphological changes of local scouring pits. The test results show that the local shear stress of the pier is gradually attenuated during the local scouring process of the pier，and the tidal current causes a large bed shear stress. However，due to the short acting time，only a large amount of sediment is started in the initial stage，and in the subsequent stage of fast water，the local scouring of the bridge pier is rapidly developed. The greater the tidal bore intensity and Froude numbers of the tidal height，the stronger the local scouring of the pier. For bridge piers of square shape，in the develop process of local scouring pit，the stronger vortex structure is triggered by the higher shear strength of tidal bore，which makes the water surface flushing more intense than the side flow scouring. The rounded piers have little difference in the water surface and side scouring. Meanwhile，the square piers in the asymmetric rotation scouring have a more scouring depth than that in the symmetric rotation scouring. After the multivariate regression analysis of test data，the comprehensive calculation formula of the local scour of pier caused by the tidal tide is obtained. The formula shows that it has better prediction accuracy and the maximum error with the test value does not exceed 12%.

Abstract:To investigate the engineering problem that different arrangement angles of sand particles may cause changes in the shear properties of sands，Toyoura sand，as the Japanese standard sand，was selected to carry out the related research. First，a special rectangular container that could change arrangement angles of sand particles was used to set different arrangement angles of sand particles，and soil samples were prepared by the vacuum preloading method. Then，a fullautomatic direct shear test instrument was used to conduct the direct shear tests，and different vertical pressures were used to simulate the pressure of the overlying soil layer with different depths to explore variation rules of shear characteristics of sand soils. In the experiments，the arrangement angles of the sand soil samples were set to four degrees: 0 °，22.5 °，45 °，and 90 °，three different vertical pressures were set for each different particle arrangement angle，and then 12 groups of direct shear tests were carried out in this paper. The test results show that for saturated sand under drainage conditions，shear strengths of the sand soils gradually increase with the increase of arrangement angles of sand particles and the vertical pressures. With increase of arrangement angles of sand particles from 0 ° to 90 °，the shear strength of the sand soils increases by about 14%，while increases by 11% with the increase of vertical pressures from 100kPa to 300kPa. Moreover，the shear modulus of sand soils is almost constant with the variation of particle arrangement angles but increase significantly with the increase of vertical pressures. In addition，the sand soils have a decay after reaching the peak strength. The shear strength decay rates of sand soils increase slightly with the increase of particle arrangement angles but remain almost constant with different vertical pressures.

Abstract:DaliLijiang highway is located in the northwest of YunnanGuizhou Plateau with the lacustrine soft soil ground. The gravel pile composite foundation is adopted to increase the bearing capacity of the lacustrine soft soil ground. The field application of gravel pile foundation in the southwest highway soft ground treatment is discussed and studied. The basic features of lacustrine soft soil along the highway are investigated using the field and laboratory test data. Then，the effect of gravel pile on the bearing capacity of natural lacustrine soft ground is evaluated based on the field monitoring data. The "Composite modulus homogenization" and "typical pile group element method" are adopted for the simulation of gravel pile foundation in lacustrine soft ground based on FLAC3D. Simulation results show that under the flexible foundation of highway，the use of crushed stone composite foundation with crushed stone cushion is effective to improve the bearing capacity of deep soft ground.〖KH*2D〗

Abstract:To design and calculate the barwrapped cylinder concrete pressure pipe (BCCP), the calculation method of external load and section internal forces of BCCP is proposed by referring to the specifications of PCCP in this study. With the consideration of the contribution of the protective cover to the stiffness of whole pipe section, the formulas for calculating the stress and strain of pipe core, cylinder, steel bar and protective cover in BCCP are put forward by using the assumption of the linear distribution of stress and strain on the crosssectional surface under different load combination. The work, elasticity and strength limit state design criteria are followed in the design, and the specific criterion conditions of each limit state are given. An embedded BCCP with an inner diameter of 2000mm is selected for examination. The results show that the judgment indexes of the pipe are smaller than the corresponding design criteria and the structure is safe.

Abstract:In order to study the influences of the coupling effect of corrosion medium and fatigue load，concentration and pH value of corrosive solution on the corrosion fatigue life of the electric wire，a new test device was designed to test some old electric wires. By prefabricating the notch on the surface of the electric wire，the effects of different corrosion conditions，corrosive medium and fatigue load on the mechanical properties of the electric wire containing defects were studied. The fatigue SN curve and fitting equation under different loading conditions were obtained，and the weights of concentration and pH value of corrosive solution on the electric wire life were analyzed respectively. The results show that the electric wire life under the coupling of corrosive medium and fatigue load is significantly lower than that without considering the corrosion action. With the increasing acidity of the solution，the electric wire life is shortened significantly. The high concentration of chlorine ion has a certain inhibitory effect on the dissolution and diffusion of oxygen in the solution，resulting in weakened corrosion effect of solution on electric wires. This indicates that the change of chlorine ion concentration is not negatively correlated with the fatigue life.

Abstract:This paper introduces the technical foundations of operating system verification theory, language, and tools, and elaborates new verification methods and concepts such as the verification path, refined relationship verification and largescale verification. The research content, verification methods, main contributions, and latest developments of multiple operating system verification projects are compared and analyzed. Meanwhile, this study also analyzes the problems in the process of operating system verification and believes that the high cost of verification and the limitations of verification tools are the key factors that restrict the formal verification of operating system. With the improvement of verification tools, frameworks and theorem libraries, new technologies such as deep learning have been improved and applied, thus more security properties of the operating system can be formally verified.