An automatic generation method of geological cross-sections in dredging engineering based on 3D geological solid models is presented. The 3D geological models are built applying the non-uniform rational B-splines (NURBS) technique, and a 2D profile can be calculated and generated automatically through Boolean operation to meet the demands of dredging projects. Moreover, an automatic marking method for geological attributes is put forward based on database technology, and the geological attributes include the profile name, scale, horizontal and vertical relative coordinates, geological lithology, and 2D standard lithology legend. At the same time, the automatic marking method can also provide an interactive mode for geological engineers to edit and modify the profile in the modeling system. Practical engineering applications show that the automatic generation method is a simple, flexible, fast and precise visual graphics rendering process that can create 2D standard profiles automatically and efficiently. This method also provides a convenient support tool for geological engineering digital analysis.

This paper investigates the wave attenuation properties of the double trapezoidal submerged breakwaters on the flat-bed by conducting physical experiments subjected to linear and cnoidal incident waves. The method of Goda’s two points is used to separate the heights of incident, reflected and transmitted waves based on the experimental data. The possible factors affecting the wave attenuation properties of the double trapezoidal submerged breakwaters (i.e., the relative submerged water depth, relative breakwater spacing, wave steepness and relative wave height) are investigated with respect to the reflection and transmission coefficients. The results show that there is a range, within which the breakwater spacing has little impact on the reflection coefficient, and the transmission coefficient tends to be a constant. The influence of the wave steepness is reduced while the breakwater spacing is too large or too small. Within the range of the relative wave height tested in this study, the reflection and transmission coefficients increase and decrease with the relative wave height, respectively. The double trapezoidal submerged breakwaters model indicates a good attenuation effect for larger wave steepness, big relative wave height and within the range of the relative breakwater spacing between 12.5 and 14 according to linear and cnoidal waves. The changes of wave energy spectra between the double submerged breakwaters on the flat-bed are investigated by the fast Fourier transform (FFT) method, showing that wave energy dissipation can be reached more effectively when the relative breakwater spacing is 12.5.

It is of importance to study and predict the possible buckling of submarine pipeline under thermal stress in pipeline design. Since soil resistance is not strong enough to restrain the large deformation of pipeline, high-order buckling modes occur very easily. Analytical solutions to high-order buckling modes were obtained in this paper. The relationships between buckling temperature and the amplitude or the wavelength of buckling modes were established. Analytical solutions were obtained to predict the occurrence and consequence of in-service buckling of a heated pipeline in an oil field. The effects of temperature difference and properties of subsoil on buckling modes were investigated. The results show that buckling will occur once temperature difference exceeds safe temperature; high-order pipeline buckling occurs very easily; the larger the friction coefficients are, the safer the submarine pipeline will be.

It is difficult to analyze the inter-relationship for the construction layout of a reservoir project scientifically and intuitively. According to the characteristics of broad field and huge information, the modeling methods of digital terrain and solid model as well as the techniques of texture mapping and scene navigation are adopted. The simulation system is developed by C program language, which includes the functions of the interactive navigation of 3D scene, the visual inquiry of project digital model information, the storage and management of project information. A certain reservoir is taken as a case. The 3D visual analysis for the construction layout and engineering information are obtained. The proposed system is of great advantages in dealing with large amount of information and the method provides a theoretical basis and technical support for the construction layout of a reservoir project.

Due to the complexity of earthwork allocation system for the construction of high concrete face rockfill dam, traditional allocation and planning are not able to function properly in the construction process with strong randomness. In this paper, the working mechanism of earthwork dynamic allocation system is analyzed comprehensively and a solution to fuzzy earthwork dynamic allocation is proposed on the basis of uncertain factors in the earthwork allocation of a hydropower project. Under the premise of actual situation and the experience of the construction site, an all-coefficient-fuzzy linear programming mathematical model with fuzzy parameters and constraints for earthwork allocation is established according to the structure unit weighted ranking criteria. In this way, the deficiency of certain allocation model can be overcome. The application results indicate that the proposed method is more rational compared with traditional earthwork allocation.

The functional piezoelectric ceramic smart aggregate (SA) sensors and actuators, based on piezoelectric ceramic materials such as lead zirconium titanate (PZT), were embedded into the reinforced concrete beams with three-point bending under static loading for purposes of damage detection. The SA actuators generated the desired sine sweep excitation signals online and the SA sensors received and detected real-time signals before and after damage. The wavelet analysis and statistical characteristics about damage signals were used as a signal processing and analysis tool to extract the optimal damage information and establish a statistical damage detection algorithm. The damage index-based wavelet analysis and damage probability-based probability and statistics were proposed by PZT wave-based theory and active health monitoring technology. The results showed that the existence of cracks inside largely attenuated the amplitude of active monitoring signal after the damage of beam and the attenuation was related to the severity degree of damage. The innovative statistical algorithm of damage pattern detection based PZT-SA can effectively determine damage probability and damage degree, and provide a prediction for the critical damage location of reinforced concrete structures. The developed method can be utilized for the structural health comprehensive monitoring and damage detection on line of various large-scale concrete structures.

In order to design and predict the dechlorination processes for remediating the halogenated aromatic compounds in the biobarrier system applied in situ, an anaerobic continuous-flow column was set up with the introduction of an enriched 2, 4, 6-trichlorophenol (TCP) reductive dechlorinating consortium. The fates of TCP and its metabolites were simulated according to the first-order sequential dechlorination kinetic model. The enriched TCP anaerobic dechlorinating consortium dechlorinated 100 μmol/L TCP to 4-chlorophenol (4-CP) via 2,4-dichlorophenol (DCP) in 10 d. The consortium was predominated with the phylum of Firmicutes and Bacteroidetes, based on the PCRdenaturing gradient gel electrophoresis (DGGE) analysis. After the consortium was applied to the column, the experimental data in the steady state were fitted by the least square method, and the first-order dechlorination kinetic constants from TCP to 2,4-DCP, from 2,4-DCP to 4-CP and from 4-CP to phenol, were 1.58 d⁻¹, 2.23 d⁻¹ and 0.206 d⁻¹, respectively. According to the fitting results, the required biobarrier width for the complete remediation of TCP, 2,4-DCP and 4-CP were 126 cm, 130 cm and 689 cm, respectively. The dechlorination/ degradation of 4-CP must be increased when the technology is applied to the real site.

Based on minimum output energy, an improved blind multiuser detection algorithm is proposed by the use of Hopfield neural network. Compared with traditional algorithms, the proposed algorithm does not need the circuit for constraints. The resources are greatly saved and the complexity is reduced as well. The simulation results show that the performance of the improved algorithm is similar to that of the optimal multiuser detection algorithm which is not suitable for the mobile station. Compared with the traditional gradient blind multiuser detection algorithm, the convergence speed of the improved algorithm is quickened.

Based on the nonlinear continuum damage model (CDM) developed by Chaboche, a modified model for high cycle fatigue of TC4 alloy was proposed. Unsymmetrical cycle fatigue tests were conducted on rod specimens at room temperature. Then the material parameters needed in the CDM were obtained by the fatigue tests, and the stress distribution of the specimen was calculated by FE method. Compared with the linear damage model (LDM), the damage results and the life prediction of the CDM show a better agreement with the test and they are more precise than the LDM. By applying the CDM developed in this study to the life prediction of aeroengine blades, it is concluded that the root is the most dangerous region of the whole blade and the shortest life is 58 211 cycles. Finally, the Cox proportional hazard model of survival analysis was applied to the analysis of the fatigue reliability. The Cox model takes the covariates into consideration, which include diameter, weight, mean stress and tensile strength. The result shows that the mean stress is the only factor that accelerates the fracture process.

Palletizing robot technology has been applied more and more extensively in logistics automation field. But there are some limitations in the current single-arm palletizing robot that it cannot do effective work in the process of moving back to the taking-end and the mechanical arm has so many freedoms that its control system is relatively complex. Based on the translating cam principle, a novel palletizing robot is designed. The horizontal movement of the palletizing mechanical arm is controlled by changeable outer slides, and the vertical movement is controlled by partitioned up-and-down spindles. To improve palletizing efficiency, the single palletizing mechanical arm is changed into multi-arm. Moreover, to improve its kinematic properties, the acceleration operating performance, joint driving force and palletizing trajectory are optimized through the multi-objective delaminating sequence method. According to the optimization results, the 3D model of the multi-arm palletizing robot is built in Pro/E, and the kinematic simulation is made. The simulation results show that the novel mechanism and optimization parameters are rational and feasible. This novel palletizing robot has the advantages of cam mechanism, so it simplifies the driving mode of palletizing movement and can lower the requirements for controlling system. At the same time, it can increase palletizing efficiency further by adding mechanical arms.