Applied Mechanics and Materials Vols. 580-583

Abstract: Linxia basin is a late Cenozoic fault-block basin along the border between the Tibet plateau and the Loess plateau in Northwestern China. Its formation and sediments’ record may be directly affected by the structural dynamics and the uplift of the Tibet Plateau. For this reason, we studied the mineral characteristics of the Maogou formation of Miocene sediments using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The XRD results showed that quartz, chlorite, illite, calcite, plagioclase, orthoclase, kaolinite, and trace palygorskite are present throughout the sequence of the cross-section in Linxia basin. In contrast, gypsum and ankerite occur occasionally in the upper portion of the Miocene deposits. The content of calcite varied with layers in the profile and was relatively concentrated in mudstone. Chlorite and illite were observed transforming into palygorskite under SEM observation. Based on the mineral characteristics and the change of mineral composition, especially the clay minerals, it could be inferred that an arid environment prevailed in the region with warm and cold intervals during Miocene time.

Abstract: The development effect of Song Fangtun Oilfield is mainly restricted by two factors which are geology and exploitation. In view of the main control factors in oilfield development, we selected two indexes,monthly average decline range and water content escalating rate to establish early warning system of blocks development effect. The system which has great practical application value, is sensitive to reflecting the monthly variation process of block development effect, and plays a certain guiding role in the development effect during the whole year.

Abstract: The boot-shaped landform is steep for upper part and gentle for lower part, which is suffering from serious landslide and collapse hazards, and the Puzi landslide studied in this paper is in boot-shaped landform. Stability analysis of Puzi landslide was taken on the detailed analysis of the tectonic setting, formation lithology and the meteorological hydrological conditions. The result demonstrates that the Puzi landslide is on the critical to unstable state. And it is possible to integral slide under the influence of rainstorm or continuous rainfall and has higher risk of geohazard. It is recommended that people settled in the landslide area should be relocated and early warning monitoring should be carried out immediately. The results will offer technical support to prevent and relieve of geohazard in mountainous areas of southwest China.

Abstract: Landslide investigation in the center part of loess plateau reflects that most of large-scale old and ancient landslides lie on river terraces at different heights, but the small ones usually occur along the sides of V-shaped loess valleys, which implies that there is an inherent connection between the landslides and the erosion action. Since river terraces were formed by intermittent uplift of the crust, which controls the features of river erosion and the thickness of loess on the terraces. The analysis of typical loess landslides in this region shows that during relative static period, lateral erosion was dominated, so river valley was widened, which induced some large-scale landslides because the toe of slope was strongly eroded. While during the uplift period, vertical erosion was dominated, and the loess began to deposit on the terraces above water level, with the downcutting of the river, a narrow V-shaped valley formed, and then small loess landsides occurred on both sides of the rivers. Therefore, intermittent crustal uplifts not only led to the formation of multi-degree of terraces, but also induce alternative occurrence of large-scale and small loess landslides.

Abstract: In the reinforcement of coal gangue slope treatment, it is difficult for hole and construction with traditional method, self-drilling anchor method was adopted, Slope stability safety factor was calculated with slope stability analysis software under coal gangue slope and self-drilled anchor reinforcement coal gangue slope, and finally the anchor pipe processing technology, construction methods and the production of grouting process and framework were introduced, which provided the practice for similar engineering.

Abstract: The appearance and development of deformation and loss of stability in the slope of cut is closely related with such interior causes as the qualities of layer rocks. Some external incentives like meteorological conditions, hydrology and process of construction are the main factors leading to the deformation of slope and its development. Three problems of deformation of slope, which is one of the common geographical hazards. The thesis, making an analysis of the geographical environment, the process of deformation and mechanism of destruction on slope of the right cut in Guangle Road K142+320~K142+740, reveals the key factors of deformation and damages of slope and proposes a reasonable realignment methods about slopes, which has achieved a good engineering effect and set a good example for the other similar slopes to be strengthened and improved.

Abstract: Two-dimensional landslide model system is an important experimental platform for studying geological disaster, landslide behavior in different conditions are achieved by controlling the hydraulic pump drive model platform uplifting cabinet inclination. During the process of automation transformation of the two-dimensional landslide model system, control system based on computer is used to achieve a smooth lifting and precise angle of landslide model platform. Thanks to predictive control algorithm of least squares support vector machine (LS-SVM) model used in this paper, random real-time change of equivalent load applied on the hydraulic cylinder system effectively solved. The control system of the two-dimensional landslide model effectively eliminated crawling effect and pulse lifting in the condition of low speed and high load conditions of hydraulic system.

Abstract: Monte Carlo simulation provides a probabilistic method to evaluate the physical behavior of earth dam. Therefore, the behavior could be got in a more realistic manner. Based on the theory, an innovative software program code is developed by combining the Monte Carlo and finite difference methods to predict the performance of earth dams after impounding. In order to assess the efficiency of the method, the case study of earth dam, located at Southeast of China, has been studied in detail. The performance of this dam is predicted and compared with the field monitoring by using the monitoring data. The results shows the robustness of the proposed method.

Abstract: Test point load test requires relatively small load, its instrument is portable, it can be easily applied to on-site testing,which may pave the way for the development of the fieldstrength of rock mechanics test, widely promoted in engineering construction, has a large space for development. When selecting the uniform rock do the load and saturation points uniaxial compression test respectively, and comparing the analysis of the two trials correlation between the results obtained by the method, the results showed that: point load test as a qualitative and semi-quantitative indicators are needed to meet the requiement of project, but if we put it as a fully quantitative indicators ,which will lead to large errors,and even lead to sweeping errors.

Abstract: Through the test of artificial frozen soil of cretaceous formation soil sample, study the mechanical properties and thermophysical properties of cretaceous formation artificial frozen soil with different soil properties and subzero temperatures. Results indicate that, uniaxial compressive strength of artificial frozen soil of cretaceous formation soil sample linearly increases accompanied with drop in temperature, with identical soil properties and water content; with decreasing temperature, elastic modulus increases and Poisson’s ratio decreases, in the case of the identical soil and ambient temperature; with decreasing temperature specific heat of artificial frozen soil decreases and thermal conductivity increases.