Applied Mechanics and Materials Vols. 105-107

Abstract: Reinforced concrete piles are often used to support highway embankments in soft soils. The performance of floating piles differs significantly from that of end-bearing piles. A numerical analysis was conducted to investigate the soil stress concentration ratio, pile and soil settlements, pile axial force, negative skin friction (NSF) and the location of the neutral plane (NP) during embankment filling and consolidation of soft soils when the soft soils is treated by using reinforced concrete floating piles. The results indicate that the pile axial force as well as negative skin friction is closely time dependent and increase much more quickly during the embankment filling than during the consolidation. The location of the NP exhibits a complicated variation as the pile head loads and the surcharge applied on the soft soils are varying with time. Most of the embankment load is born by pile for the existence of soil arch within the embankment.

Abstract: With the rapid development of urban construction, the shield construction technology has been greatly developed. Shield tunneling method generally adapts to relatively uniform soil, soft rock and sand rock strata, and the shield tunnel construction has been more mature for the homogeneous strata. However, for the soft and hard interbedded strata, how to solve the problems of breaking the hard rock, increasing the tunneling efficiency and reducing the construction costs, are difficult problems in the shield tunnel construction. In this paper, based on a great deal of theoretical analyses and engineering practices, the effective methods of improving the efficiency of tunneling, reducing cutter wearing and decreasing the construction costs in the process of the shield tunneling construction in hard rock and gravel layer are proposed.

Abstract: All rock mass engineering projects are closely related to rock mass material property. The methods of obtaining these properties decides the project design’s safety and reasonable. The varied characteristics of rock mass under force are subjected by their texture, construction and tectonic history. The experimental results imply that the rock mass strength, deformation and failure modes are all effected by following aspects, including the test controlling method, machine stiffness and the sample size, etc,. In order to use the test results to guide the practice projects, we must first know the natural status and engineering propagation process of rock mass, then design suitable experimental scheme, subsequently, the more fit for the natural results of rock changed process will be appear. According to the analysis of previous research achievement and newly test results, we can investigate the rock mass stability and predict its failure.

Abstract: This paper is based on a series of experiments on saline soil which is sampled from the west of Jilin province. Through analysis of the properties of material composition, we reveals the inner connection between the dispersivity of saline soil and the soil’s practical environment and material composition, which has theoretical and practical significance in engineering practice and study of saline soil’s dispersivity in this area .This paper will help us fully understand the characteristics of dispersive saline soil and the way it behaviors in engineering for taking the feasible engineering countermeasures to cope with saline soil and engineering accidents caused by the dispersivity of saline soils. The results of this paper will bring engineering applications of dispersive saline soil to a new level.

Abstract: For the flaw of safety evaluation system using safety factor as control index, seismic permanent deformation is used to evaluate the safety of earth rock fill dam. In this study, the seismic deformation of Zipingpu dam after Wenchuan earthquake is measured and analysis. The deformation in the middle of the riverbed on the crest is the largest. The deformation in the left dam abutment is smaller than that in the right. The seismic permanent deformation on the crest grows rapidly in the first three days, and then develops slowly. The results show that deformation grows along the height of dam with the relation of exponential or power function.

Abstract: In order to study the foundation pit supporting structure displacement of the change rule and different parameters on the transverse displacement effect of pile. My research based on supporting structure engineering of Shenyang Washington. We use the software ADINA as a research tools to establish a finite element model. We simulated and analyzed the displacement with and without anchor. Results show that adding anchor supporting played a very good supporting effect, and the simulation results and actual test results compared and analyzed proved reasonable and simulation design scheme was feasible, this excavation has some guidance for the engineering and a certain reference for similar deep foundation pit bracing. ^[1]

Abstract: The paper is based on information of permafrost engineering geology of National Road 214, and for a comparative, analysis the permafrost engineering geology features of National Road 214, Including permafrost ground temperature, ice content, natural permafrost table and artificial permafrost table; Then Summary the distribution of permafrost of National Road 214, including Southern limit of permafrost and Northern limit of permafrost, Then get one conclusion; Because of the outside temperature increase and under the influence of the role of the project, frozen ground temperature has rise trends, The permafrost along the road all tended to degenerate, Then summary its degeneration features of National Road 214, and analyze the reasons of the final degeneration; Final, combining the high-speed reconnaissance and design project National Road 214, Analysis the permafrost existing meteorological data and geological survey data, according to the frozen ice content and permafrost thickness, Then to predict and analysis permafrost degeneration tendency in numerical simulation.

Abstract: Low pile foundation is spacious used to process irrigation structure. In Vietnam it is effectively used to process irrigation structure in the north plains. However, when calculating load of the foundation works, it was mainly calculated to transmit to pile omitted load transmit to surrounding soil, in fact the load was transmitted to surrounding soil. So the lager number of piles were used to process foundation, it caused waste of piles and economics. Therefor calculating pile foundation, as calculated the interaction interaction between Soil, piles and irrigation structure will reduce the number of piles in the foundation, and when the irrigation structures were deformation tested by software and measured in actual condition, the results showed that the irrigation structures were guaranteed to work as the normal design criteria. Now in Vietnam some of pump stations and aqueducts are applied the interaction between Soil, piles and irrigation structure to process foundation.

Abstract: The failure of concrete dam is a process started from local failure to global instability, and there is a huge scale difference in the process, so the analysis should be conducted in a multiscale manner. Choosing a typical failure curve as a signal, the precursor load is determined in the form of singularity point in the curve. With a numerical example, the previous reported methods for determining precursor load are compared with the wavelet approach, and it is shown that the wavelet approach gives more accuracy and reasonable results. Besides the precursor load, the failure mode, local failure or global instability, can also be figured out by the wavelet approach. By applying it to the Jinping arch dam, the obtained results are in good consistency with geology mechanical test. It is shown that the wavelet approach is of good applicability and accuracy for dam failure analysis.

Abstract: Based on the data from Basin hydrology, weather, runoff, land use, soil, DEM and with ARCGIS9.0 and WMS7.0 applications, SCS small basin hydrological model can be applied in Lanhe basin Distributed Hydrological Model. Within each sub-unit, net rainfall can be calculated with SCS-CN, and conflux using SCS dimensionless unit hydrograph, while river network flow concentration using subsection Muskingum method. By conducting the simulation of distributed rainfall runoff where measured runoff value are selected from 20 historical flood, the results indicate there are 14 values that are effective and the ratio comes to 70 percent. And there are 11 effective values after conflux test to the 14 floods where the ratio comes to 80 percent. The process of calculating runoff matches well with actual measure which indicates that the Distributed Hydrological Model is a scientific and precise model and can be applied to basin water flood forecast and water resource management.