Applied Mechanics and Materials Vols. 90-93

Abstract: Slope of subhorizontal layer structure is among typical natural structures and the different soft and hard rock combinations in upper and lower slope parts differ in seismic response. Taking into consideration some slope failure phenomena of two-sided slopes with banded structure ridges in “5.12” Wenchuan Earthquake, simulation experiment are made to research two types of horizontal structure slopes with hard-upper and soft-lower and soft-upper and hard-lower parts, by means of numerical simulation analysis and simulating experiment on vibration table. Research results show that for slope with hard-upper and soft-lower parts, its upper hard rock body is inclined to undergo global shearing deformation, along contact layer with underlying soft rock body, and the upper slope body is apt to go through collapse and pull-crack. For slope with soft -upper and hard -lower parts, influenced relatively more strongly by its lower hard rock part, rock body possibly shows cracking deformation similar to sliding and compression cracking, which may extend upward or downward along the contact layer. Moreover, the shoulder of two-sided slope is apt to undergo pull-crack and that, to some degree, relieves integral stress and sliding deformation of the upper soft rocky body. Therefore the whole rock body goes through little sliding deformation. Research result confirms the actual shatter slope failure, which further verifies the view that horizontal seismic action force plays main role in slope failure.

Abstract: On the base of the obtained materials and considering the factors of composition features, dynamic mechanism and deformation-motion characteristics, the three-dimension numerical simulation model is generated. And the parameters of Young module, passion ratio and shear strength are obtained. Then the calculation conditions are extracted from the combination of the inducible factors and the displacement features. After that, the deformation failure are simulated by the FLAC3D code, and the results are compared to the monitoring data. The results indicate that the influence of the water impoundment on the stability of the landslide is small, the water descending is large. For the front part monitoring points, the amounts and the curve shapes of the numerical calculation results are accord with the practical ones, but for the monitoring point in back there are only the similarities in the curve shapes, and the amounts are a little smaller.

Abstract: According to the basic characteristics of geological environment in Pingyao mining area, we analyzed the relationship between coal mining and the ground fissure disasters in recent years. The result shows that the mine goaf is the essential factor for the formation of ground fissure, and the precipitation and groundwater drainage accelerates its development. Based on a systematic analysis of classification of goaf as well as the distribution characteristics and the formation mechanism of ground fissure, we found that the ground fissure in this area is non-tectonic, and thus proposed corresponding prevention and control measures. Research results would provide basis for the improvement of local environmental conditions and the control of geological disasters.

Abstract: During the construction for solving geological hazard of landslide, there often existed the accidents of sticking pipe and burying drilling caused by borehole collapse. It resulted that drilling tool couldn’t be pulled out, and scraped the drilling tool and borehole. So it was necessary to research a kind of pneumatic hammer which could realize drilling at normal work, and push out the drilling tool by reverse impact when the formation collapse caused sticking pipe and bury drilling. In order to research profoundly the pneumatic hammer work mechanism and describe piston movement laws in detail, physical model was established according to the actual conditions, finite difference method was adopted, thermodynamics and kinematics were applied. Using object-oriented programming, the bidirectional pneumatic hammer software was developed whose integrated development environment was VB. The software could calculate acceleration, velocity, displacement, pressure, temperature of the front and back air chamber at any time and the operating performance parameters of the pneumatic hammer. Not only the bidirectional pneumatic hammer, but also the unidirectional pneumatic DTH hammer and the no-dig impactor were designed by the software.

Abstract: The conventional shear creep apparatus uses lever to amplify the load, which has a serious limitations in practical use. First, the round and small shearing box can easily form an obvious stress concentration in the margin area. In addition, tilting of the lever can give an unreal vertical load in loading process. Aiming to solve the shortages of conventional apparatus, a new type of shear creep apparatus is introduced in this paper, whose loading system apply the pulley block, and shear box is changed from the round with the area of 30cm² into the present square one with 10×10cm². The new shear creep apparatus has more advantage compared with the conventional, and is more satisfactory to the need of test.

Abstract: The working mechanism of branch pile under vertical load is studied based on digital image correlation method in model test. Bearing capacity and deformation characteristics of equal-diameter pile and branch pile are obtained during the analysis. The study results show that the bearing capacity of branch pile is higher than that of the equal-diameter pile. The displacement field around equal-diameter pile is divided into the pile side and pile tip deformation regions, destruction pattern of single pile is similar to the Meyerhof's destruction pattern. Soil beneath branch generates a shear sliding surface under the ultimate load, and the soil beneath pile tip shows a pricking destruction pattern.

Abstract: With the expansion of Ningdong Energy and Chemical Industry Base at Lingwu, Ningxia, water shortage is becoming increasingly serious and then has become one of the main factors in restricting the development of society and economy in the region. In the paper, through a systematic analysis of the re-use ways of the sewage as well as the water-saving potential for agricultural purposes, it is suggested that water right trading is the solution when part of the surplus can be used for industrial purposes in the Base, thereby leading to a more reliable way of sustainable water supply and a sustainable and steady economic growth in the region.

Abstract: Due to the applicable installation height, small mass, flexible characteristic, and small damp, the adherent billboard could easily result in vibration with the wind effect. The main factor is the turbulence among the cause effects. Combining the structural dynamic theory, and considering the characteristic of the adherent billboard, a wind effect calculation formula is set up considering the turbulent wind that is resulted by the 1st vibration type. Hope to provide some reference for similar structure designs.

Abstract: In the interest of forecasting and alarming system of rainfall landslides, the Boji stones landslide of Three Gorges is taken into researching. On basis of the model, its epitomized model is formed to analyze the landslide mechanism and damage model by taking them into consideration: water-level fluctuation in reservoir, rainfall intensity, rainfall capacity and soil mass mechanical property, and decide current stability, predict its tendency and potential risks through applying the monitoring data and quantitative analysis. The research indicates that Boji stone landslide in flowing reservoir is in stability without any extra dynamic

Abstract: The fills of barrier dams commonly result from high-speed landslides debris flow. In this paper, four model tests were conducted to study the effect of fill size on the stability of barrier dams. The failure time, failure mode, pore pressures and earth pressures were then observed and analyzed. The results show that barrier dams composed of coarse-grains or well-graded fills are more stable than those composed of fine-grained fills; coarse-grain-dams are more sensitive to the rising of water level than fine-grain-dams; the failure mode of coarse-grain-dams is usually overflowing-erosion and the barrier dams usually fail from the top of dams; the failure mode of fine-grain-dams is sliding and the barrier dams fail initially from the slope downstream.