Applied Mechanics and Materials Vols. 170-173

Abstract: This paper proposed new method of testing a moisture content of the crude oil which is based on BP neural network. It describes the principle of BP neural network model and calculation method to predict the moisture content of crude oil. The normalization of evaluation index and the implementation process of this method in computers. In the end, an application example of this method used in the process of practice and precision control requirements.

Abstract: As the development of exploiting marine resources, many ocean platforms were built. But there is still a problem unsolved completedly. The suction force between seabed soil and ocean platform perplexed jackup technically and is discussed in the article. The comparisons between model experiments and Skempton's Model are much helpful to realize the significance of suction force.

Abstract: The non-uniformity feature of rock joints’ surface profiles is the main influencing factor of the sampling representativeness. In order to analyze the sampling representativeness of rock joints statistically, the joint roughness coefficient (JRC) of 18 pieces of natural slate rock structural plane samples with size from 100mm to 1000mm were measured. The results show that it is necessary to evaluate the representativeness of rock joints in engineering practice due to the large non-uniformity of JRC. The total variation of JRC for different measurement sections, sizes and samples indicates that the sampling representativeness can be evaluated by the average value and the distribution probability of JRC; moreover, the sampling representativeness should be considered the statistical law evaluation of JRC for the concrete size and sample, and offered the accurate standard in changing range.

Abstract: The slope stability is an important problem for the slope building on the soft clay ground. At present, the vane shear strength is common used to calculate the factor of slope stability at short term. In fact, a lot of cases show that the vane shear strength underestimates the real shear strength of the sliding surface. Therefore, based on Mohr-Coulomb theory, and using the linear relation between the vane shear strength and the depth, a method of converting in-situ vane shear strength into undrained shear strength parameter is presented. Two shear strength parameters c and φ are from statistical regression analysis. The anisotropy, the lateral compression coefficient and the average consolidation degree of the soft clay are considered. The two shear strength parameters are used to calculate the short term safety factor of the slope stability. The safety factor is greater than 1.0 for steady slope.

Abstract: This paper taked Xiaosha River constructed wetland as the study object, the difference of the constructed wetland and Xinxue River constructed wetland as a demonstration project were studied theoretically by constructed wetland model, virtual data were constructed and amended by the difference. The application of constructed wetland differentiation during actual modeling process was studied. In the actual project, there was important guiding meaning on design, construction and operation management of the constructed wetland in this study.

Abstract: The hazard evaluation index system is divided into basic factors and vulnerability factors, According to the actual data collected in the Himalayas Geological Survey and the main factors index of geological disaster harm degree in study area were extracted in accordance with the evaluation index system. Using GIS to digitize, statistic, overlay, merge, classify and spatial analysis the basis of geological data. The weight of each evaluation factor can be exhibited according to the prediction to disaster survey points using BP neural network and the training and testing of the sample data using neural network inversion process, then the hazard evaluation to the research area can be processed by using this weight to have a direct overlay analysis. The regional hazard evaluation was completed using disaster points and area statistics. There is a realization of the evaluation unit grid, factor comparison, factor overlay, and an accomplishment of the facture about the thematic maps of evaluation results according to the secondary development of MAPGIS.

Abstract: Reliability of water-sealed conditions is crucial to the safety of water-sealed oil-storage. With a case study of underground water-sealed oil storage cavern in Huizhou, a reliability evaluation index system of water-sealed conditions is estabilished based on the main factors influencing water-sealed conditions. Also, a zonal evaluation of water-sealed conditions of the cave rock mass ranging from 0m to -70m is made by Fuzzy Analytical Hierarchy Process. Moreover, a three-dimensional numerical seepage model is established to study the seepage laws of the groundwater before and after the cavern excavation, and the water inflow during excavation and operation can be forecasted too. The results prove that the cavern site is suitable for the construction of large-scale underground oil storage caverns for its good water-sealed conditions and high reliability.

Abstract: At present, due to various reasons, cannot do a large number of field measurements, and the measured results often can only reflect the local stress field distribution. What’s more, the measured results has discreteness, it’s difficult to describe the law of the initial stress field distribution in the entire region. This paper combines topographic and geological conditions and the measured in-situ stress value of Jinping I hydropower station dam area, using FLAC3D4.0, select geological section profile of II1 exploration line for reference, to simulate the incised process of the valley. We get the stress field distribution when rock gravity acting alone, and exert horizontal tectonic stress based on the calculate result of gravity field in the VI terrace model. We inversion the distribution of current Valley stress field, and validate the rationality of the design after compare with the measured data. We obtain the features of stress field of current valley. And we also proved that the regional principal compressive stress plays a decisive role in the formation of the current valley stress field.

Abstract: Slope stability estimation is an engineering problem that involves several parameters. Artificial Neural Network (ANN) and Support Vector Machine (SVM) have been successfully used in slope stability problem. However, there are some open issues for above-mentioned methods, which are very hard to overcome. For this reason, Gaussian Process Regression (GPR) which has a theoretical framework for obtaining the optimum hyperparameters self-adaptively has been used in slope stability problem. Without complicated mechanics computation process, through learning the empirical knowledge coming from real engineering, the complicated nonlinear mapping relationship between slope stability and its influencing factors was established easily using GPR. The results of test study indicate that the method is feasible, effective and simple to implement for slope stability evaluation. The results are better than previously published paper of ANN and SVM.

Abstract: Many slope areas in Malaysia whether it is man made or natural slope are particularly vulnerable to soil erosion and shallow failures due to the increasing of soil moisture and porewater pressure. This study will determined the active root zone of the tree near the toe of the slope which suctions have been generated within this section. Hence, the effect it only focusing on hydrological aspect with soil moisture pattern near vicinity of the tree. The mechanical aspect of tree root such as tensile strength and bonding between root and soil which can led to increasing soil strength are assumed negligible in this study. From preliminary result of field monitoring show significant increase of total suction at near vicinity of tree which can lead to stability analysis on slope. The comparison of FOS will be presented between at the toe of slope with and without the tree. Furthermore, for slope studies area the reresult indicates that tree induced suction can be related to cause the factor of safety against slope failure improve up to 33.07%.