Applied Mechanics and Materials Vols. 638-640

Abstract: China has Suffered from the Landslide a Lot, which Mainly are Large and Giant Slope Slide. in the South-West of China and Three Gorges Reservoir Region, Landslide has Caused Great Lost to the People's Production and Living.Thus,building the Efficient Landslide Monitoring System is Not only Beneficial to Avoid the Occurrences of Landslide by Engineering Method, but also could Reduce the Lost Caused by Landslide. at Present, China Landslide Monitoring has Reached the International Advanced Level. the Monitoring has Large Monitoring Range with Various Methods. in this Paper, the Landslide Monitoring Method has been Classified by the Aspects of Monitoring Means and Monitoring Objects. According to the Difference of Monitoring Means, the Various Landslide Monitoring Methods could be Divided into Five Different Kinds, such as Macroscopic Geological Observation Method, Simple Monitoring Method, Setting-Station Monitoring Method, Instrument Monitoring Method and Auto-Telemeter Method.Meanwhile,basing on the Difference of the Monitoring Objects, the Landslide Monitoring could be Divided into 5 Categories, which are Deformation Monitoring,earthquake Sound Monitoring, Strain Monitoring,hydrographic Monitoring,environmental Factors Monitoring and Etc.It Provides Certain Reference Significance for the Selection of Landslide Monitoring Means According to the Differences of Monitoring Objects.

Abstract: This paper aims to study the distribution characteristics of the ratio of measured value and calculated value for ultimate bearing capacity, shaft resistance and tip resistance, and discuss the impact of shaft resistance and tip resistance on ultimate bearing capacity. A new performance function is proposed in terms of the three types of bearing capacity mentioned ahead. Take bored piles and driven piles for example, and the results from analysis indicate that the ratio of the measured value to calculated value of bored piles ranges from 0.75 to 1.45, and mostly is greater than 1.0; The ratio of the measured to predicted bearing capacity of driven piles lies between 0.8 and 1.5, and is larger than the corresponding ratio of bored piles. In addition, the reliability of tip resistance is lager than that of shaft resistance for bored pile, while the reliability of tip resistance is less than that of shaft resistance for driven piles. Meanwhile, the method presented in this paper can offer references to designers for revising and improving the technical code for pile foundations.

Abstract: In recent years, the application of super-long piles gradually increased, therefore the research about effective pile length is imminent. This paper summarized the meaning of effective pile length from two different points, bearing capacity and settlement. Analyzed its application and discussed the advantages and disadvantages of the various effective pile length calculation methods, it has the important guiding significance and application value to the reasonable pile length design of the present actual project.

Abstract: Based on exponential flow law, the analytical solution to the one-dimension consolidation governing differential equation was deduced when the laws of permeability and compressibility coefficients with depth can be expressed as exponential function. By finite difference method, the numerical solution of excess pore water pressure and degree of consolidation was obtained, then the reliability of numerical solution is verified by comparing numerical results with analytical results, and consolidation behavior of non-homogeneous layer with exponential flow law under various parameters is analyzed. The results showed that under the condition of the two-sided drainage, the heterogeneity of foundation consolidation of index of seepage speed depends on the index of the size and the size of the non-uniform parameters. That is when the index m is bigger, increase the permeability coefficient, reduce the compression coefficient, the consolidation is faster, but the inhomogeneous parameters are still play a decisive role.

Abstract: Based on the gradient theory, the gradient dependent nonlocal friction model is established. It is a new model which can describe the nonlocal friction effect. Based on Mindlin’s solution of displacement, an elastic solution of the lateral frictional resistance for ultralong friction pile is derived. The ultralong friction pile is analyzed by using the gradient dependent nonlocal friction model. Compared with the solution to the local friction law, the results shows that nonlocal friction law is feasible and reliable. The study is helpful for understanding the friction mechanism in geotechnical problems. It is a good attempt to set up the more actual and more accurate friction model.

Abstract: To meet the requirements of foundation bearing capacity, end bearing piles are adopted by most of the Sluices built on soft soil foundations. However, after the completion of the sluice, there will be settlements on both sides of the backfill, which will result in base cavity, form water seepage channels, and endanger the buildings and dams. In this paper, a new steel sheet pile diaphragm wall scheme is proposed to resit seepages under this situation. Steel sheet pile diaphragm walls are disposed on the river side of the building and connected with the chamber floor to prevent wound infiltration and sliding sideways. The practical results show the effectiveness of the proposed scheme.

Abstract: Referring to a project in Tianjin, the paper has described the mechanism of the earth berm, and analyzed the influence on supporting structure from the earth berm using finite element. It was observed that the wider of the earth berm with constant height the smaller of the supporting structure deformation, and the deformation will tend to be stable when width reaches specific value. With constant width, the higher of the earth berm the smaller of the supporting structure deformation. The retaining of the earth berm should be reasonable and safe. Under the premise of the slope stability, the paper suggests that the height of the earth berm should be 2/3 of the excavation depth, and the width should be 1/2 of the excavation depth.

Abstract: Construction projects are increasingly encountered bad foundation, because of collapsible loess is widely distributed in our country, so most widely especially bad in collapsible loess foundation, this paper based on the characteristics analysis of the loess collapsibility of loess, expounded in combination with the engineering practice of collapsible loess foundation treatment methods, problems and countermeasures.

Abstract: Rayleigh wave exploration has broad application in engineering geological investigation, underground cave detection, highway nondestructive testing, etc. On the basis of introduction about the principle of transient Rayleigh wave exploration, the process of multi-channel transient Rayleigh wave exploration and data processing with an engineering example are stated. Compared to the field drilling histogram, reasonable explanation for the local deviation from the Rayleigh wave exploration result is given. Besides, the advantages and disadvantages of multi-channel transient Rayleigh wave exploration are also discussed, indicating a widely applicability of the Rayleigh wave exploration and some problems that need further research.

Abstract: The influence of rainfall on slope stability problem that highway, railway,water conservancy and energy engineering production must consider and study, the rainfall is one of the major factors causing the soil slope failure。Establishing model test of red clay slope, rainfalling the model, the paper analyzing the moist frontal edge, power water pressure, slope displacement under the rainfall. The result has some reference value for fundamental mechanism of rainfall infiltration induced landslides in a red clay slope.