HXYFYX-Current IssueCurrent Issue
http://192.168.0.205:8088/Jwk_wk2013
EN-UShttp://192.168.0.205:8088/Jwk_wk2013/EN/current.shtmlhttp://192.168.0.205:8088/Jwk_wk20135<![CDATA[Some problems in design of geosynthetic-reinforced soil structures]]>During the past three decades, geosynthetic reinforcement has been used extensively in geotechnical structures, but the mechanism of interaction between reinforcement and soil is not fully understood, as a result, the conservatireness in the design is found frequently. The conservatireness of design method for geosynthetic-reinforced soil structures is examined. Some discussions on the design of geosynthetic retaining walls, reinforced fill slopes, reinforced embankments over soft soil foundations and reinforced piled embankments are presented. On the basis of the recorded strain and stress in a number of published field case histories, the conservatism of design is further pointed out. It is indicated that the research on the interaction between reinforcement and soil is very important, and that the design method on basis of deformation coordination is necessary.]]><![CDATA[Comparative analysis of model tests on different types of composite foundations]]>Nine groups of model tests on the geocell-reinforced cushion, bag-sand well, gravel pile and flexible pile composite foundation are completed to analyze the consolidation effect of different types of composite foundations based on the similarity theory. Some conclusions are drawn as follows: (1) the inclusion of horizontal reinforcement can spread the upper load and raise the bearing capacity, and the reinforced effect of geocell is superior to that of geogrid; (2) the effect of pile groups cannot be neglected when analyzing composite foundation with piles and their bearing capacity is superior to that of horizontal reinforcement composite foundation obviously; (3) the volatility of bearing capacity of piles and soil changes under different loading ranges, and that under single-pile loading range is higher than that under three piles and seven piles. The pile-soil stress ratio of the pile head of gravel pile composite foundation is larger than that of gravel pile + geogrid composite foundation. The smallest is gravel pile + geocell composite foundation, but for the foundation of flexible pile types is flexible pile + geocell composite foundation larger than flexible pile + geogrid composite foundation, and the smallest is flexible pile composite foundation; (4) the pile-soil stress ratio of bottom pile of bag-sand well and gravel pile composite foundation is about 1 and for the flexible pile composite foundation it is much larger and the largest value is about 24; the pore-water pressure is larger and the velocity of dispersion is faster in shallow foundation than those in deep foundation of pile. The pore-water pressure, and that is bigger of piles composite foundation is larger than that of soft soil foundation and geocell-reinforced composite foundation, and the outflow velocity of bag-sand well and gravel pile composite foundation is faster than that of flexible pile composite foundation.]]><![CDATA[Evaluation of double-shearing type kinematic models for granular flows by use of distinct element methods for non-circular particles]]>2 model) are three types of double-shearing kinematic models, which formulate the plastic flows of granular materials. These models incorporate different physical interpretations of angular velocity. A developed distinct element method program NS2D is used to generate assemblages which are composed of elliptical particles with aspect ratios of 1.4 and 1.7, respectively. The assemblages are then subjected to undrained simple shear tests to validate the above-mentioned models. The results show that: (1) the postulation in the double-sliding free-rotating model seems to be unduly restrictive for not considering the effect of particle rotation on energy dissipation; (2) a quantitative and qualitative difference between the observed rotation rate of the major principal stress axes and the theoretic angular velocity does not support the double-shearing model; (3) the DSR^{2} model presents a successful prediction of the angular velocity by means of the averaged micro-pure rotation rate (APR), and it can be used to study the non-coaxiality of granular materials; and (4) the APR is a rational and important variable which considers the effect of particle rotation in the energy dissipation process, and bridges discrete and continuum granular mechanics.]]><![CDATA[Earthquake-induced permanent deformation of rockfill dams based on cumulative damage theory]]><![CDATA[Layerwise summation method for ground foundation settlement based on Duncan-Chang constitutive model]]><![CDATA[Distribution rules of axial stress of reinforcement in reinforced earth retaining wall]]>xof the axial stress in the reinforcement is x≤ L/2 (Lmeans the reinforcement length). The axial stress in the reinforcement of reinforced earth retaining wall will have only one maximum value when the reinforcement is horizontal, and multi-maximum values will arise when the reinforcement is concave or convex along the reinforcement length. The reasons of the occurrence of multi-maximum values of reinforcement axial stress in reinforced earth retaining wall and the phenomenon of the potential rupture surface close to the wall panel near bottom wall can be explained according to the research results.]]><![CDATA[Laboratory simulation and theoretical analysis of piping mechanism under unsteady flows]]><![CDATA[Interpolation algorithm for shallow foundations settlement based on compression and load-settlement curves]]>e-pcompression curve, which can be deemed as the upper limit of the practical foundation settlement with the same base pressure, while p-ssettlement curve can reflect the deformation characteristics of the foundations of small size, which can be deemed as the lower limit of the practical foundation settlement with the same base pressure. Based on the above theory, an interpolation algorithm for the foundation settlement is proposed, and the issues of determining the modulus of compressibility are transformed into those of finding the interpolation functions. This algorithm can reduce the absolute error produced by the traditional algorithm to the relative error within a certain range so as to improve the calculation accuracy of foundation settlement. Furthermore, a method to predict the foundation settlement is suggested by adopting two load test results under different load plate sizes, whose rationality is verified through four-group plate load tests on the same foundation. And the interpolation function of a circle foundation is derived and analyzed to show the process of foundation settlement calculation through the interpolation method. The analysis results show that the foundation settlement curves gradually change from concave to convex when increasing the size of foundations. The proposed method combines the results of the consolidation tests and plate load tests, which can reflect the settlement characteristics of the foundations of different sizes. It is suitable for promotion in engineering practices with its clear theoretical and experimental basis and simple and convenient calculation process.]]><![CDATA[Long-term field observation of sediment consolidation process in Yellow River Delta, China]]><![CDATA[Numerical analysis and fluid-solid coupling model tests of coal mining under loose confined aquifer]]><![CDATA[Adsorption of nitrogen and water vapor by sliding zone soils of Huangtupo landslide]]><![CDATA[Influence of shallow soil improvement on vertical bearing capacity of inclined piles]]><![CDATA[Development and application of large-scale multi-functional frozen soil-structure interface cycle-shearing system]]><![CDATA[Loosening zone and earth pressure around tunnels in sandy soils based on ellipsoid theory of particle flows]]><![CDATA[Change of pore water pressure in soil as filter cakes formed on excavation face in slurry shield]]><![CDATA[Effects of shear rate on shear strength and deformation characteristics of coarse-grained soils in large-scale direct shear tests]]><![CDATA[Numerical simulation of electro-osmosis consolidation considering variation of electrical conductivity]]><![CDATA[Leaching behaviors of cement-based solidification/stabilization treated lead contaminated soils under effects of acid rain]]><![CDATA[Stochastic analysis method of critical slip surfaces in soil slopes considering spatial variability]]><![CDATA[Development and tests of large-scale inclined direct shear apparatus]]><![CDATA[Experiment study on dynamic parameters of artificial polycrystalline ice]]><![CDATA[Experimental study on performance of GRS bridge abutment with flexible face]]>D, between abutment foundation and panel of retaining wall on the ultimate bearing capacity of GRS bridge abutment, deformation characteristics, strain of geogrids and earth pressure are comprehensively and comparatively analyzed. The test results show that the ultimate bearing capacity of GRS abutment exhibits a remarkable increase tendency with the increase of D/H_{L }(H_{L}, height of geogrid-reinforced retaining wall) before D/H_{L}=0.4 for GRS retaining wall with the length of geogrids supposed to be equal to the height of GRS abutment, and the maximum ultimate bearing capacity can be obtained when D/H_{L}=0.4, which is followed by a significant decrease while Dis greater than 0.4H_{L}. Before failure happens to GRS abutment, the settlement of abutment foundation and top surface of GRS behind abutment tends to be linear and the differential settlement reaches the lowest level when D/H_{L}=0.4, and the ratios of horizontal deformation of panel to the height of lower wall are less than 1%. Moreover, horizontal deformations at top of lower walls are significantly greater than those in the middle and at the bottom of lower walls. Additionally, the maximum values of strains of geogrids occur and keep to be away from panel with the increase of D/H_{L}, and the strain level of geogrids in the lower wall and upper wall is almost the same as that when D/H_{L}=0.4. Therefore, the optimum performance of GRS bridge abutment can be obtained simultaneously.]]><![CDATA[Centrifugal model tests on post-construction settlement of high embankment of Hechi Airport]]><![CDATA[Fundamental period formula for horizontal layered soil profiles]]><![CDATA[Influence of uniaxial tensile strain on filtration characteristics of geotextiles]]><![CDATA[Optimization technology for geogrid-reinforced subgrade widening projects of highways]]><![CDATA[Model tests on initial freezing process of column foundation on slope in permafrost regions]]><![CDATA[Stress distribution of reinforcement of reinforced soil structures under drawing force]]>G existing at the reinforced soil interface, a pull-out coefficient E_{r} that relates to the tensile modulus E_{r }and G, is established, and thus the formulas for stress distribution and the relative displacement along the geosynthetics are derived. The feasibility of the formulas is confirmed by comparing with the existing experimental data. Then the stress transmission way of geosynthetics with the increase of tension and the influence of α on stress distribution of geosynthetics are analyzed. It is shown that α can be better used to reflect the influences of many factors such as stress, friction and soil properties on the tension of geosynthetics. In the structure of reinforced soil, the proposed formulas are better to estimate the tension of geosynthetics under small displacement.]]>