Advanced Materials Research Vols. 446-449

Abstract: Large-scale reinforced earth retaining wall model test has been Designed and completed. The model size is 3.0mχ0.85m χ2.0m(lengthwidthhigh) Slope angle is 70º, Fill with the use of red sandsχtone construction site preparation materials By entering a different amplitude and frequency of the sinusoidal load, to discuss the law of Dynamic characteristics of the model wall and fatigue life under the repetition load. The results showed that, the fatigue life has a linear relationship with the stress amplitude of three reinforced structures ,the logarithm of fatigue life changes with the stress amplitude sensitivity of Gabion reinforced earth retaining wall is low than Geogrid reinforced retaining wall does. The results help to reveal the instability mechanism under cyclic loading, and provide a useful reference for designing the reinforced retaining wall engineering.

Abstract: via the red mudstone proceed of the unconsolidated and non-drained triaxial compression test, the research in different degree of compaction reinforcement material under the influence of red mudstone strength. To the different reinforcement layers, different ambient pressure test, analyses not reinforcement material layer number of decorate the more the better, decorate three layer of steel material is better than the four layers of reinforcement decorate material sample. The analysis in different degree of compaction element soil and reinforced soil under test result, the reinforcement material that can obviously increase the strength of the soil, and in different degree of compaction soil under the different strength, and with the degree of compaction to improve the stress-strain relationship curves by strain softening type to strain change sclerosis type. Analysis of the С value of the red mudstone compaction degree with the increased and rise, but theφ rise and reduced.

Abstract: This paper has carried out soaking load test, routine soil test, X diffraction, scanning electron microscopy on coarse-grained soil in Gobi region, analyzed the coarse-grained soil collapsibility and explored the mechanism of collapsibility generation. The results showed that: the coarse-grained soil in Gobi region had a high degree of collapsibility; mineral composition, microstructure and salinity constituted the main internal reasons resulting in such phenomenon. In soaking conditions, the cementation strengthen between grains reduces, the structure is damaged under external force and the grain movement leads to greater settlement.

Abstract: The strength, deformation and hydro-mechanical behaviours of a compacted unsaturated Gaomiaozi bentonite-sand mixture under undrained condition are studied by conducting a series of isotropic compression tests and triaxial shear tests under constant water content. During undrained isotropic compression testing, void ratio and suction decrease while degree of saturation increases. The stress-strain relations are obtained from undrained triaxial shear tests. The volume contraction and lateral expansion can be observed. The suction decreases with increasing shearing. The net confining pressure and initial dry density affect the initial rigidity, undrained shear strength, volumetric deformation and hydro-mechanical behaviour.

Abstract: The method of cement grouting in surrounding soil can be used to fundamentally prevent and cure the shaft lining rapture by its dual effects of release and restraint vertical addition force. The results show that this technique can effectively improve the stress condition of shaft lining and the vertical additional stress of the shaft lining can be released and restrained. The stress release effect is most evident in the deep of the shaft lining and changes in a descending order from the deep to the top. In grouting process, the cement grouting parameters should be adjusted according to the stress state of shaft lining that is monitored , it can ensure the safety of the shaft and reach the reinforcement effect. So this technique can prevent and cure the rupture and ensure safety of shaft lining by means of postponing the rupture time.

Abstract: On the basis of Hsiung’s normalization analysis method, the soil is assumed to be in accordance with the elastic-plastic model. Some normalized parameters are selected to normalize different load-displacement curves to a single one, which is obtained by using the parabolic load transfer function. At last, we get a regression formula of the single curve with the regression analysis method. By comparing the results of regression formula with the practical test data of projects, the fact that the calculation results of regression formula coincide well with test data show that this analysis method is correct and it can provide reference for the research and application of uplift pile.

Abstract: This paper presented the results of centrifuge model tests conducted to investigate the behavior of cohesive soil slopes under the vertical surface load, considering the bolt-shotcrete supported slopes. The cement layer and bolts influenced the behavior of the slope when surface vertical load was applied. The analysis of bearing capacity and displacement threw light on the failure and displacement distribution of the slope.

Abstract: The clogging problem occurs in the dewatering projects of sludge with high water content and high clay particles content can be solved by the aeration-vacuum dewatering method. And the water in the sludge can be separated out quickly. Through the dewatering model test of the sludge with this method, the effects of vacuum degree and aeration rate on the dewatering results are studied. The relationship between the initial and final water content is got under the aeration-vacuum condition. Through the fitting analysis of the dewatering curves, the predict model for water content of dredged sludge is presented. And the effect mechanism of the vacuum degree and aeration rate are analyzed.

Abstract: Vibration model can reflect conductors nonlinear vibration under wind excitation .The paper improves and expounds the detailed derivation process based on the previous studies, and studies the movement type of conductors. Comparing with the vertical displacement change of conductors in different conditions to prove that the model derived is reasonable. The paper analyses conductors nonlinear vibration in the case of external condition change to study the movement change of conductors. Lyapunov stability theory and Routh-Hurwitz criterion are used to obtain critical wind velocity of conductors, namely the conditions for conductor galloping. The results shows model derived can reflect conductors nonlinear vibration under wind excitation.

Abstract: Sekiguchi and Ohta model is a well-known elastoplastic constitutive model which can simulate the initial anisotropic behavior of K0 consolidated soils. In this paper, the impact of load direction on the yield surface of this model is well studied by firstly deriving the equation of the yield surface satisfied under different load directions and then by drawing a series of yield surfaces under different load directions (between 0°~90°) in p-q space. Results show that the shape of yield surface changes a lot with different load directions. As the load direction changes from 0°to 45°, the inclined yield surface shrinks, and the angle of inclination decreases as well, which means the anisotropic degree of the yield surface is decreasing. These results are new findings on the study of the anisotropic yield surface for K0 consolidated soil.