Advanced Materials Research Vols. 1065-1069

Abstract: According to retaining walls of joint construction buildings and office building of the mine of three yuan weizi town, outdoor pavement reinforcement of engineering practice, introduced the design parameters and construction process of the high-pressure jet grouting pile, soil nail wall and drilling grouting, the results showed that reinforcement scheme is reasonable and feasible, there is reference to other similar projects.

Abstract: Model tests are performed to study the working properties of reinforced and non-reinforced gravel cushion on soft subsoil. The effects are analyzed of reinforced materials on the bearing characteristic of the cushion. The stress field and settlement field are studied through the method of numerical simulation. The results show that: The bearing capacity of foundation with cushion increases significantly when the cushion is reinforced. Under the same condition, the effect of geocell reinforcement is better than geogrid reinforcement. The value of coefficient of subgrade reaction increases when the cushion is reinforced. The reinforced materials can adjust the stress distribution and settlement distribution of the cushion.

Abstract: The soft soil in Pearl River Delta regions is characterized with high water content, high compressibility and low bearing capacity. Therefore, when building the structures on such foundation, it’s necessary to pay attention to the deformation and stability. The projects' practice shows that, when analyzing the stability on foundation pit or slope with soft interlayer, it should not only calculate the overall stability of the slope, but also calculate the stability or bearing capacity of the foundation. Although sometimes the stability of the slope meets the requirements, it doesn’t means that the bearing capacity of the foundation meets the requirements because of the existence soft interlayer, the limitations of the circle slice method and the difference between the sliding surface and the actual sliding surface.

Abstract: Wu-Bauer hypoplastic model may simulate cross-anisotropy of sand. The cross-anisotropy of the deposited sand is distinguished with the angle between deposited plane and direction of the principal stress in the Wu-Bauer hypoplastic model. The parameters considering cross-anisotropy in the model are determined by fitting experimental data with optimization. By virtue of intergranular strain tensor, the cross-anisotropy Wu-Bauer hypoplastic model is revised under dynamic load. Finally, the different deposited angle is computed by the revised model. It is shown that the revised Wu-Bauer hypoplastic model can simulate cross-anisotropy of sand and distinguish quantitatively strength and deformation of deposited sand in different loading direction under cyclic load.

Abstract: Steeply inclined seam is a seam whose angle of dip ranges from 45° to 90°. Uneven subsidences of Goaf will damage the structure of the buildings on the ground surface, if improper choice and handling of foundation and buildings, part of the building will crack, tilt, until collapse. In this paper, we have a research on the area of goaf of steeply inclined seam, using numerical simulation to theoretically research and predict on the regulations of settlement, horizontal displacement, stress change of ground in goaf from now on to 20 years later. And this provides us theoretical basises and necessary suggestions for the use of ground in goaf and the safety of buildings.

Abstract: Just because that saturation-line is a primary factor to affect both security and stability of tailing dam, it is of great significance to define its location and distribution. Different sand body moisture contents of the saturation-line up-down layer lead to distinctive dielectric properties, which is essential to geophysical prospecting. On the basis of feasibility study of using radar to detect the saturation-line, the approach is applied practically in one dam. It is predicted that Ground Penetrating Radar (GPR) not only has a series of advantages such as intuitional image, shorter work period, greater detective depth, less interference to dams; but also can acquire calculable depth and location data, which can forecast holistic distribution of the saturation-line from a macroscopic view, and of which diagrams and results can offer reliable basis on safety, early warning analysis and security management.

Abstract: It is the components, living things evolution processes, development environments, distribution layers and the earliest time for coal series formation that are investigated and studied in detail based on the author’s graduation thesis, the “Geobiology” , the “China coal petrology” and the other’s some references in this paper. And it is considered that mainly two types of the Coal Series might be distinguish in the geologic history in China, respectively consisted of the lower organisms (especially the lower plants, blue-green algae) and higher organisms (especially the higher plants, pteridophyta, gymnosperms, Anthophyta). Meanwhile, the conclusions can be drawn that the development of the organisms is not only controlled by the environments, on the other hand, the environments and their sediments are also affected by the ecologies of the organisms. So the coal bed or coal series can be used as the marks of the environment explanation, perhaps having some Significances of Geobiology. In additional, the relationship with an unconformity or disconformity is discussed here, too.

Abstract: Compared with pile-supported reinforced embankments, rigid-flexible pile composite foundation with geogrid reinforced cushion (RFPCFGRC) has its advantage of its economics. Piles play an important role in rigid flexible pile composite foundation with geogrid reinforced cushion. The bearing mechanics of RFPCFGRC is more complicated than that of pile-supported reinforced embankments because of addition of flexible piles. This paper discussed the diffence and the bearing mechanics of the two types of composidte foundation. The results show that addition of flexible piles has changed bearing mechanics of composite foundation and changes the load distribution among piles and soil. Soil arching degree of RFPCFGRC is larger than that of pile-supported reinforced embankments.

Abstract: Based on the safety and durability in the complex environment, the experiments on unconfined compression strength about the cemented soil after eroding in sodium sulfate solution have been carried out and the influential laws of different concentration of sodium sulfate solution and eroding time on the cemented soil unconfined compression strength have been obtained. The test results show that the different concentration of sodium sulfate solution and eroding time may have influences on erosion effect of unconfined compression strength of cemented soil at different levels. If the ionic concentration of sodium sulfate solution is small, the solution has little erosion effect on the unconfined compression strength of cemented soil. But the unconfined compression strength will decrease with the increase of eroding time, and the erosion effect of unconfined compression strength will increase with the increase of eroding time. The study result is significant and valuable to the safety and the durability of cemented soil engineering.

Abstract: This paper presents a new vacuum preloading technology in which hydraulic fill is used for sealing while the sand cushion is not necessary. Thus this technology is applicable for projects with scarcity of sand resources.This paper dedicates the characteristics of this technology, reinforcement mechanism, applicable scope, construction technique, reinforcing effect and prospects, in an effort to provide guidance and promote the application of this technology.