Applied Mechanics and Materials Vols. 501-504

Abstract: The safety of the earth structures is highly dependent upon the fill compaction quality. Recently developed nondestructive testing techniques (NDT) present many advantages in comparison with conventional field density measurements. Therefore, use of NDT in monitoring of the fill quality appears to be attractive for future pavement geotechnics applications. This paper presents an alternative technology using non-destructive Clegg impact tester for compaction control in silty sand. 132 compaction tests and impact tests with varying values of compaction effort, moisture content, and density were conducted in laboratory. Each observed impact value (Iv) was then considered as a function of its corresponding compaction effort, moisture content and dry density. Results of the study show that for the silty sand tested, the variations of Iv with moisture content are similar to the corresponding unique moisture-density compaction relationship. The values of Iv generally correlate well with moisture-density relationship for each compaction effort. Along with a speedy moisture tester, dry density can be predicted using target Iv values in a fast and efficient manner based on current standard specification.

Abstract: Based upon the characteristics of micro-pile in building heightening and transformation (mainly including the mechanism of the press injection increasing the bearing capacity , the rigid connection between micro-pile and its original foundation), through the analysis of its load characteristics in building heightening and transformation, using the theory of pile foundation constructed in reverse order, then the mechanical mechanism of micro-pile and original foundation is studied and the analysis method of soil-pile-foundation (cap) interaction by considering pile tip penetration displacement and soil compression between pile shafts is demonstrated.

Abstract: In engineering design and construction, the adverse effect would be prevented, if we can estimate and consider the the foundation transformation and control or take advantage of it.Calculating the building foundation settlement. we should consider the influence of lateral deformation of foundation soil. In this paper we replace e-lgp curve with e-p curve on basis of the calculation theory foundation settlement considering three-dimensional transformation, it makes the calculation of foundation settlement more simplified and accurate.

Abstract: In recent decades，there have been detailed investigations of bearing capacity of muddy dolostone through in-suit static load and uniaxial compressive strength．By analyzing test datas，the vertical bearing capacity, uniaxial compression and water ratio were studied．The bearing capacity which will be performed on slight , medium、strong weathering ,muddy dolostone．By the fact that the single axis compression strength and the water ratio experiment study to the slight weathering 、the medium weathering 、the strong weathering muddy dolostone, explain that making use of fitting equation to come to oppose guessing the bearing capacity of the foundation, is feasible，above all for medium and strong weathering muddy dolostone．

Abstract: The C90 high performance concrete was prepared with crushed cobblestone, washed riverbed sand, special mineral admixture. The crushed cobblestone was crushed from cobblestone which particle size was larger than 160mm. The crushing quality coefficient of the cobblestone was above 80%. The gradation of the crushed cobblestone must accord with 5-20mm continuous grading. The compressive strength of HPC90 was above 40MPa in 1d and 103.9MPa in 28d. At the same time, HPC90 had good ability in anti-crack, impervious and anti-freezing-thawing performance.

Abstract: In order to investigate the relation between uniaxial compressive strength and point load strength, several homogeneous rock specimens were tested, and the influence of the different rock type was investigated using regression analysis and the derived equations were statistically tested. The test result show that there are some correlations and trends between uniaxial compressive strength and point load strength, the shape size and lithology of rock specimens have important influence on the result of point load test, and the greain size, the mineral compositon and the structral compact are key factors. It is difficult to realize that using one or several function to describe all internal relations between uniaxial compressive strength and point load strength.

Abstract: Construction site-monitoring on adjacent existing building’s pile foundation,using ANSYS finite element software to simulate the deformation of adjacent pile foundation when foundation pit excavation. Combined with measured data to analyze the interaction of foundation pit excavation and adjacent existing building’s pile foundation and draw the conclusion that the measured settleme-nt of pit’s adjacent pile is greater than the model’s theoretical value and the pit excavation has certain influence on the pile foun-dation’s vertical displacement of existing buildings.

Abstract: Experimental measurements described in this paper are a continuation of research focused on interaction of foundation concrete structures and subsoil. This problematic has been researching on the Faculty of Civil Engineering VSB - Technical University of Ostrava for long time. Is it one of the main research directions at the Department of Constructions. In 2013, the research was focused on the analysis of fiberconcrete foundation structures. Especially, It was tested a foundation slab model of the National Supercomputing Center IT4 Innovations. This significant construction is realized in campus of VŠB - Technical University of Ostrava right now. It was a big opportunity to compare a model test results with measurements from real construction.

Abstract: Considering three contact states of good contact, containing weak interlayer and water, containing weak interlayer but no water, a series of cyclic triaxial compression tests of soft rock-concrete samples for investigation the dynamic deformation behaviors are carried out. The influence of contact states on dynamic properties of combination samples is analyzed based on the dynamic stress-strain curves and accumulative strain curves. The results show that changing the contact states has notable effects on the dynamic strain of the samples. Comparing with the good contact sample, the accumulative strain of the sample containing weak interlayer is about 2 times. The amplitude of the sample vibration increases, while the accumulative strain reduces with the increase of the vibration frequency. It can be noted that the measures such as assuring construction quality, removing weak interlayer and water, keeping good contact state between bedrock and tunnel structure can reduce the settlements and improve the tunnel service life.

Abstract: Geology in plateau regions is complicated, season changing have great influence on subgrade filling, it is difficult to fill the subgrade. This paper is based on the project of S308 in Qinghai. According to the study on construction scheme, control standards, laboratory experiment and test in-suit, this paper gives the conclusions about subgrade construction technology in plateau regions, which can direct the project construction relevant.