Applied Mechanics and Materials Vols. 99-100

Abstract: The usage of fly ash in constructing expressway is more and more extensive and the technology of constructing is becoming to more and more mature. But the stability and failure mode of the embankment is lack of researches. In order to study the stability and failure mode of the embankment, the plan for the study of the static model test of light fly ash embankment was designed, in which the model material was selected based on the similarity principle of the model test. The mechanical characteristic under static load is simulated. The internal force, the relationship between the stress and load, the displacement and load of different depth of the embankment were obtained through the test. The deformation and mechanical characteristic is studied and the influence of concrete pavement is also considered. The experimental results show that the high filling subgrade has an excellent stability and high bearing capacity and the influence of the concrete pavement is relatively large.

Abstract: To inject in coarse sand strata and medium sand strata with cement grout is difficult in subway engineering. To test the component, particle size and viscosity of THE II sand consolidation agent ,the engineering property is got.To calculate the groutability of the grout material in gravel sand strata, coarse sand strata , medium sand strata and fine sand strata of Shenyang strata,it is feasible to inject the grout material into shenyang sandy strata.Research and engineering indicate that the grout material is high groutable and the reinforcement effect is good.

Abstract: The excellent mechanical properties of reactive powder concrete (RPC) are tested with under the condition of hot water conservation. Four batches of 19 specimens are prepared to determine the best ratio of RPC component materials. The variation of strength (compressive strength, flexural strength) of RPC with fly ash or tailings powder is studied with two batches of 10 specimens, and its optimal dosage is determined.

Abstract: Rare earth element (REEs) concentrations were measured for groundwater and wall rock samples from two aquifers (sandstone and limestone aquifers) in Renlou coal mine, northern Anhui Province, China. The results indicate that groundwater from these two aquifers are rich in REEs as expressed by their Nd concentrations (0.012 and 0.008 μg/L). They all show heavy REEs enrichment with low NdRN/YbRN ratios (0.35 and 0.40) when normalized to their aquifer rocks. Y- Ho fractionation are only observed for groundwater from limestone aquifer with high Y/Ho ratio (97 in average), whereas groundwater from sandstone aquifer have low Y/Ho ratios (24 in average). The former is considered to be related to the release of Y and Ho from calcite with different partition coefficient. The similarity of some REEs between groundwater and aquifer rock, as well as the different rock composition of aquifers, provide possibility for discrimination of water sources by using REEs, and Y/Ho ratios and Eu anomalies are expected to be useful in Renlou coal mine.

Abstract: Abstract. Micron fly ash/SBS modified bitumen composites were prepared by melt intercalation. The physical properties and ageing properties of micron fly ash/SBS modified bitumen were investigated. The results showed that micron fly ash/SBS modified bitumen exhibited a decreasing penetration, an increasing softening point, and a decreasing ductility. Compared with that of SBS modified bitumen, the anti-aging property of the micron fly ash/SBS modified bitumen becomes worse.

Abstract: In this paper, through analyzing the differential element of silos wall suffering from axially symmetric load according to their actual working status, the author applies the theory of taking account of moment to getting silos internal forces and displacements ,and gives the differences in the calculation results gotten respectively using nonmoment theory and the theory of taking account of moment through an example. What to be thought, during the course of designing to code for design of reinforced concrete silos, is brought.

Abstract: A two dimension atypical elastoplastic model was introduced to study the problem of rock pressure in engineering excavation under high ground stress. This model was established on the base of description of slip line grids in local orthogonal curvilinear coordinate, in which discontinuity of displacement field in excavation was depicted with a combination of two smooth functions. A analytic model for rock pressure of circular opening was given through strict mathematic deduction. Rock pressure of opening is quite less than ground stress, which demonstrates that bearing capability of surrounding rock plays an important role. It is concluded that depth, size and shape of opening, physical and mechanical properties of surrounding rock, and support rock pressure of circular opening have great influence on rock pressure.

Abstract: All kinds of mining enterprises prefer to use computer-aided design (CAD) in drawing figures of mining reserves. CAD is convenient to operate and ensures the creation of intuitive and beautiful figures. However, CAD causes data error easily due to human intervention. Moreover, CAD wastes time and is prone to omit records. To reduce the incidence of such errors, the current paper examines the transformation of CAD-drawn reserves’ figures and databases into “block” form. This paper also aims to realize the conversion of figure blocks and databases using Visual Basic (VB) in CAD and database applications. To achieve this result, the circle and text are first extracted from CAD form. Then, a series of changes is implemented. Lastly, figure blocks are endowed with new properties. Using this approach can quickly transform figure elements into block properties, achieving good application effects.

Abstract: Network security situation awareness is a new technology for network security monitoring and early warning, and is a hot spot in the area of network security. In this paper, the artificial immune technology is applied to the study of network security situation awareness, and a model is presented and implemented. The paper adopts the artificial immune-based intrution detection technology to real-timely monitor network attacks, and introduces vaccination mechanism to effectively improve the real-time network attack detection abilities of network hosts. In addition,the paper puts forward the concept of network group according to idiotypic immune network theory, and establishes a real-time and quantitive network risk assessment sub-model based on antibody concentration. The changes of antibody concentration are not only related to intrusion intensity, but also to interactions with antibodies in the same network group. To predict future network security situation trends,the paper adopts time-series prediction mechanism based on cloud models. Theoretical analysis and experimental results show that the model is effective to network security situation awareness with advantages of real-time and high accuracy.

Abstract: The effects of polycarboxylate superplasticizers, naphthalene-based superplasticizers and SJ-2 air-entraining agent on the frost resistance of C50 concrete under steam-curing were studied by a rapid freezing-thawing method.The frost resistances of concrete under three different temperature condition curing are compared. The results show that the polycarboxylate superplasticizer concrete is more suitable to steam curing and has better frost resistance than naphthalene-based, especially under a low temperature steam-curing condition. When the SJ-2 air-entraining agent was added to polycarboxylate superplasticizer concrete, the frost resistance of concrete has been further improved. When the steam curing temperature is too high, the frost resistance of concrete with admixture is not improved.