Applied Mechanics and Materials Vols. 226-228

Abstract: In recent years, micro-pile has been widely applied to landslide treatment engineering due to its advantages in application and construction, and the engineering effect is very evident. Large-scale physical model test was made for studying failure mode of micro-pile group in landslide, which indicated that numerical magnitudes between the displacement and the stress of the piles are better consistent along the load transfer direction. Concentrated destruction points locate on about three times the pile diameter up and down the slip surface. Failure mode of micro-pile in landslide treatment engineering is: pile of the loaded segment usually breaks for bending moment and shear force, and back of sliding side mainly exposes to the tension role, compared to role of tension of anchored segment in front of the micro-piles and compression behind of the piles.

Abstract: Engineering designs often come upon with steady mooring problems in a wide range of port with submerged breakwater. Plane physical model is difficult to implement due to spatial limitation and, so far, there is no effective numerical method to solve practical engineering problems by two-dimensional simulation. This paper first verifies the empirical formulas for transmission coefficient of submerged breakwaters in domestic and international researches against the results of sectional physical model. The verification shows that the calculated results with the empirical formula of Yang (1981) are the most consistent with the measured data and a bit conservative. Based on Yang’s formula, porosity coefficient is used to simulate the integrated effect resulted from the physical features of overtopping, wave transmission and reflection on a prototype submerged breakwater. Then a plane physical model test is carried out to verify the simulation and the results are in good agreement. This paper provides an effective numerical simulation method for wave protection of ports with submerged breakwater.

Abstract: Firstly, in the paper based on the constitutive equation and the basic equations of the unloading fractured rock mass on the second expansion phase at the crack, the two types of variables of the energy functional about the variation problem was constructed the,as the independent variables at that stage. In order to identify the undetermined function G,the energy functional variational the independent variables ,,the variational function was satisfied the principle of minimum potential then can obtain the function G. Second, Secondly on this basis, two undetermined Lagrange multipliers were introduced to the new functional in order to absorb the balance equation and stress boundary conditions into the new functional .As the same, variational the independent variables,, then obtained the . To simplify the using the Green formula and then can be identified the undetermined Lagrange multipliers.Finally,the unloading the fractured rock mass at the crack of secondary expansion phase of the unconstrained variational energy functional can be obtained which is the generalized variational principle.

Abstract: With the large ship transportation for bulk cargo marine development, construction of modern offshore deep water wharf is becoming more and more important. Based on the view of domestic offshore deep water wharf, the jacket structure was proposed as deep water light wharf. In consideration of the structure dynamic responses and the pile foundation pull-out resistance, three types of pile foundation were adopted, which are the hollow steel piles, the reinforced concrete pile and the hollow steel piles poured with granular materials. By finite element method the vibration characteristic and transient dynamic response to wave load were calculated. The results show that the jacket structure’s dynamic response to wave is not obvious. Also the structure with reinforced concrete pile can reduce the structure vibration displacement.

Abstract: The application of vacuum preloading for soft foundation treatment in grain storage is introduced from its principle, design, construction and the inspections. Its obvious effect is proved by example. The vacuum preloading method can effectively improve the soft soil foundation’s physical and mechanical performance and increase the bearing capacity of soft soil of coastal areas. For the grain storage, oil depot especially for large reserves of oil depot project, the treatment effect is remarkable. It can be widely used in the ground treatment in the soft soil area for grain storage, oil depot construction.

Abstract: This article selected a typical loess slope engineering as the research object, and through the characteristics of loess landslide, landslide environmental geological conditions, the formation mechanism of the landslide study of the loess area of urban slope instability factors, loess slope stability of the calculation method and reinforcement measures. This paper adopts the theory of Morgenstern-Price to analyzing the stability of the slope, referencing with Sweden finite slice method, Simplified Bishop method, Simplify Janbu method. The reinforcement adopts the technology of possessed anchor to disposing the loess slope, and has good Practice effect. The loess slope stability study area has a large reference.

Abstract: This paper evaluates the stability of concrete dam under the action of fluid-solid coupling in the two working conditions of water level raising and rainfall intensity increasing with the method of strength reduction, and the conclusions are revealed as follows: The unstable failure of dam always starts from the slope base, the crack on the slope top and the creep slip in the slop base developed, which led to the gradual destruction of the dam and formed the slip surfaces through the dam; the safety factor of the concrete dam reduced and the potential slip surfaces moved to the inside of the dam with the water level raising; the more rainfall intensity, the larger plastic yield region and the lower safety factor will be, and the dam slip surfaces transferred from the base of slope to the inside of the slope top gradually.

Abstract: The pipe-soil interaction problem is a critical issue in the fatigue analysis of SCR. In this paper, investigation on the initial trench configuration in the touchdown zone (TDZ) of the steel catenary riser (SCR) and factors, which have influence on the trench configuration, such as the amplitude of top end motion were performed firstly. Then the bending moment variation at different points along the trench during the pull up and lay down, the trenches and dynamic response at the touchdown point (TDP) under different soil properties were also investigated. It should be noted that the pipe around the TDZ especially at the TDP, which bears the most drastic bending moment variation and stress variation, is the hot spot in the fatigue analysis of SCR, and the soil properties have big influence on the dynamic stress response amplitude.

Abstract: Vegetation Slope Protection Engineering was affected by several factors, and has become the focus of the geotechnical engineering. The stability of the vegetation slope must be controlled rigorous according to the surrounding environment condition and safety level of the slope in highway. According to the Grey Incidence Analysis (GIA) method of grey system theory, a new grey theory model is applied in analyzing of the characteristics of Eco-engineering protected by roots of vegetation, to attain the correlation coefficient affected by extent of the factors. After analysis of several practical Bio-engineering examples, to attain the most influencing factors of the stability of vegetation slope are the density of roots (ρ), the length of roots (L), the diameter of roots (D), the weight of soil (γ), the anti-pulling force of roots (P), internal friction angle (φ), cohesive strength(c) and the shear strength of the soil (τ). The role of factors is classified in order to define the extent of the impact and provide guidance for construction and design of Eco-engineering. After analyzing the data collected from the field and several classicistic documents, utilized Grey Incidence Analysis method to make prediction in order to guarantee the slope safety. It shows that the grey system theory can be effectively and practically adopted in the slope stability analysis of vegetation slope in expressway and that has a good prospect.

Abstract: Construction quality is one of the main reasons which lead to the failure of cement deep mixing pile. In order to ensure the construction quality of cement deep mixing pile and control its construction process, the influence of four construction parameters such as slurry conveying capacity, drilling and hoisting speed, agitation shaft rotation speed and remixing times on pile quality are analyzed. At last key reasons to ensure the construction quality of cement deep mixing pile are pointed out. Pile quality and construction efficiency should be considered when construction parameters being optimized. The research results provide reference for construction of cement deep mixing piles in the future.