Papers by Keyword: Slope

Abstract: Microfluidics is an efficient technology for controlling fluid movement in microchannels at extremely low speeds. The main advantage lies in the significant reduction of samples and reagents, thereby reducing costs and analysis times. Three devices with retention systems are introduced that are manufactured through 3D printing (SLA) incorporating microchannels with variations in levels and dimensions. Fluid velocity is studied, considering factors such as channel width, length, rounding, height, and shape. The analysis of velocity along the channel reveals liquid retention at the devices' maximum point, ensuring more precise results in microdevices.

Abstract: The bearing capacity of shallow foundation near slope has always been one of the subjects of major interest in geotechnical engineering for researchers and practical engineers. This study focuses on the numerical analysis of the undrained bearing capacity for a strip footing near a slope, and subjected to a centered vertical load, using the explicit finite difference code FLAC (Fast Lagrangian Analysis of Continua). Theoretical and experimental studies confirm that, when a strip footing is near a slope, the bearing capacity must be assessed using reduction coefficients. In this study, several geometrical and mechanical parameters have been considered in order to evaluate the effect of the slope on the undrained bearing capacity. The numerical values have been compared with those available in the literature. The results show the influence on the undrained bearing capacity of the location of the footing with respect to the slope.

Abstract: The effect of anodic and cathodic chloride contents on the macrocell corrosion and polarization behavior of reinforcing steel embedded in cement mortars were investigated and clarified. The results indicated that the higher cathodic chloride content could accelerate the cathodic reaction of cathode and make the controlling mode of macrocell corrosion changed from cathodic control to mixed control or anodic control. The higher anodic chloride content could accelerate the anodic reaction of anode and make the macrocell corrosion more controlled by cathode. These results will provide a guide to inhibiting the macrocell corrosion of reinforcing steel in concrete, which are not only useful for engineers to design and construct the new marine reinforced concrete structures, but also are helpful for engineers to repair or rehabilitate the existing chloride contaminated reinforced concrete structures, in the condition of avoiding the adverse effect of macrocell corrosion induced by the non-uniform distribution of anodic and cathodic chloride.

Abstract: The rainfall-induced slope failure is the major geo-hazard all over the world including Malaysia. Number of studies done already to investigate the process of slope failure, however the parameters that control the initiation of flowslide type of failure is still lacking. In tropical areas different mass movements occur from erosion to flow type of failure, in order to understand the mechanism will help to mitigate the posed risk. The flowslide is also type of slope failure that mostly occur in granular type soils, when initiated attain the higher velocity and fluid like motion, and it is dangerous than other types of landslides. The flowslide type of slope failure mainly due to rainfall. Field studies are timing consuming and expensive, while numerical studies requires lot of characteristics related to geology of the materials. Therefore laboratory flume experiments used in order to understand the mechanism and behavior of slope failure by changing different parameters such as density, rainfall intensity, thickness and initial moisture condition. The model slope prepared by sandy type of the soil and failure induced by artificial rainfall by installing the sprinklers above the model flume. During the experiments the pore pressure and moisture content were measured. From the detailed experimental study it was observed density of soil slope controls the initiation of the flowslide type failure. Small density of the soil slope suffers from flowslide type of the failure at smaller rainfall intensity. However in case of higher density even higher rainfall intensity accompanied with significant initial moisture conditions did not trigger the flowslide. The erosion gullies formed from toe to crest of the slope in the case of dense slope. The measurements of moisture content at the lower parts of the slope can be used as early warning of slope failure, however piezometers less reliable for prediction of slope failure in advance. Before large failure the settlement occur at the crest of the slope.

Abstract: Rainfall-induced landslides occur in many parts of the world and causing a lot of the damages. For effective prediction of rainfall-induced landslides the comprehensive understanding of the failure process is necessary. Under different soil and hydrological conditions experiments were conducted to investigate and clarify the mechanism of slope failure. The failure in model slope was induced by sprinkling the rainfall on slope composed of sandy soil in small flume. Series of tests were conducted in small scale flume to better understand the failure process in sandy slopes. The moisture content was measured with advanced Imko TDR (Time Domain Reflectrometry) moisture sensors in addition to measurements of pore pressure with piezometers. The moisture content increase rapidly to reach the maximum possible water content in case of higher intensity of rainfall, and higher intensity of the rainfall causes higher erosion as compared to smaller intensity of the rainfall. The controlling factor for rainfall-induced flowslides was density of the slope, rather than intensity of the rainfall and during the flowslide the sudden increase in pore pressure was observed. Higher pore pressure was observed at the toe of the slope as compared to upper part of the slope.

Abstract: For computation of reaction, internal force and displacement of a beam, the displacement equation from Conversion Method is used in establishing compatibility condition of deformation. In the process of Section-Conversion Method, the joints without sway is set as the coordinate criterion. Cutting the part between two joints as a base element with the method of section, it becomes a simply supported beam in form. The internal forces at the section cut are those which equivalent forces from other side of the beam. According to the axiom of action and reaction, the equivalent forces react to the other part of the beam. The displacement equations are used for all parts one by one. The precision resolutions of reaction, internal force and displacement of a beam are achieved.

Abstract: It is found from the earthquake statistics in recent decades that the vertical seismic oscillation of near field was strong. And even the recorded peak value of vertical seismic oscillation was far more than the peak value of horizontal seismic oscillation in some sites. In order to study the characteristics of vertical and horizontal seismic oscillation acceleration acted on the slope. Calculate the slope earthquake dynamic response characteristics under the horizontal and vertical seismic acceleration by the FLAC3D numerical analysis method. Compared the acceleration, velocity and the displacement amplification coefficient under two kinds of excitation. Analyzed the influence on seismic stability by the acceleration of different direction.

Abstract: The sedimentation deformation of superhigh fill in the mountainous areas is very complicated in law, and will be influenced the topographic relief, and it is specially outstanding for the sedimentation of high-fill project. For the significant project such as airport and road base, in order to guarantee the safe operation of the project during use, it is required to strictly control the post-construction and uneven sedimentation. Therefore, the stability of superhigh fill has become the key to influence the safety and stable operation of projects. In this paper, a simulated calculation is conducted to the ultrahigh fill of expansion project of an airport in Chongqing to analyze its stability, so as to provide references for the project design and construction.

Abstract: Based on the numerical simulation method and a sample slope engineer of waste dump, the failure modes of waste dump slope is analyzed. By means of analyzing working conditions such as different slope angles, single step, many steps, the failure modes of waste dump slope under different working conditions is obtained. The results show that the slope stability of multiple steps waste dump is better than the slope stability of single step waste dump, and the deformation of the slope is small.

Abstract: The red loam had abundant rainfall, rich in light and heat resource of Yunnan Province. But the uneven distribution of rainfall temporal during the year, it restricts the development of agriculture in this region. Thus how to use soil water resources reasonably and efficiency become the key to ensure crop and vegetation growth of needed water and improve the ecological environment. In this study, the key factor is district’s slope. Setting the runoff district’s rainfall intensity was 28.7mm/24h under rainfall simulation, selected four Yunnan Province read loam’ slop: 7.5°、10°、12.5°、15°.The results showed that at the same soil prophase water content and rainfall intensity, the higher runoff district’s slope will make it less time to product flow; At the beginning of product flow, flow of underground runoff was little, product flow was reached stable increase.