Applied Mechanics and Materials Vols. 580-583

Abstract: Based on the application of Rock Bolt Foundation in metallurgical industrial plant foundation design, this paper utilized bolt deformation formulas that derived by Gu Shuancheng and others to calculate deformation of rock blot. The result is consistent with the experimental value, the authors can further verify the experimental and theoretical calculation value eventually by finite element analysis software ANSYS, which provides a reference for practical application of rock bolt foundation in metallurgical industrial plant.

Abstract: To simulate the fracture of the coal under impact load, uniaxial pressure test of coal which retrieved from KongZhuang coal mine-DaTun coal and electricity Company of China coal group was done in the manner of strain control which rest with a function of uniform variable acceleration. Through researches on the stress-strain relationships and acoustic emission characteristics, the relationship between ring count rate and time series was founded, and the process before failure of coal was divided into four stages: low-level ringing count rate, higher level, highest level and peaceful period. Through the comparison and analysis, it is founded that acoustic emission characteristics in the stage of higher level of ringing count rate can be regarded as a basis for the prediction of coal fracture. According to three obvious rise stages of acoustic emission signal in the process before failure of coal, growth factor of climbing speed is introduced and the values are calculated between 2 to 4, and it is conferred that the value of is proportional to compressive strength of coal and loading rate. It is of great significance for the prediction of coal fracture by acoustic emission characteristics in the stage of new cracks.

Abstract: Come up with of pile-soil-(foundation) pile cap interaction grounded upon penetration deformation of pile ends and compression of soil between piles. Hyperbolic model is adopted to simulate the development of tip resistance and side resistance in accordance with deformation to reflect the nonlinearity of pile-soil work, Boussinesq solution is utilized to calculate the stresses generated in soil by foundation (pile cap) plate, Mindlin stress solution is used to calculate the stress produced in the soil between piles by side resistance and end resistance, and the stress of soil is the superposition of the two solutions.

Abstract: With the rapid development of traffic cause in our country, the operating requirement of driving load factors to pavement structure become higher and higher. The Semi-rigid base asphalt pavement structure exposed some defects and shortcomings, so the study of flexible base asphalt pavement structure is put on the agenda under the circumstances.Based on the research achievements at home and abroad of the existing asphalt pavement structure , choosing different elastic modulus and thickness to calculate and analyze the flexible base by ANSYS, gaining the law and trend of mechanics response (the vertical displacement and tensile stress) about pavement structure for the flexible base pavement of each layer foundation to provide the design reference.

Abstract: The horizontal displacement of pit top and horizontal displacement in deep soil of underground garage deep foundation pit in Radio and TV centre of Shandong province was analyzed. Combing the deformation control value of foundation pit, we thought that the supporting structure was safe and reliable. The supporting structure could not only meet the strength requirements but also meet the deformation control requirements. This deep foundation pit was a successful case under complex conditions. Analyzing the variation rules between monitoring data and construction time, the instructive conclusions were obtained. The deformation of foundation pit external corner was largest. The external corner should be avoided in foundation pit. The dynamic loads around foundation pit had a great influence on the safety and stability of pit. The rainfall was disadvantage factors, so the construction of foundation pit should keep away from the rainy season. The foundation pit floor could limit soil deformation and improve the safety of pit. The pit floor should be constructed as early as possible.

Abstract: At present, relatively few drilling surveys have been conducted on coral reefs, and comprehensive geological info on coral reefs is difficult to obtain. However, research of coral reef is of great importance to our development and exploitation of maritime resources. The survey of Chenhang Island in Paracel (Xisha) Islands saw China’s first usage of digital borehole camera technology, which resulted in a large amount of first-hand geological data. We have utilized the rock mass integrity index (RMDI) method in our analysis of coral reef integrity, and with reference to the rock mass classification standard, formulated the correlation between RMDI values and coral reef intactness, enabling the engineering evaluation of coral reef integrity. Through statistical analysis of camera data gathered along the CK2 borehole’s approx. 1km length, we performed an integrity evaluation of the entire borehole length using the RMDI classification, and created a coral reef stratum development diagram which is consistent with the actual cores. The results indicate: (1) the classification system based on RMDI is feasible in the integrity evaluation of coral reefs; (2) the coral reef integrity values obtained using the RMDI method are accurate; (3) borehole camera survey and statistical analysis are of great utility in the study of coral reefs.

Abstract: Both Hyperbolic model and Logistic curve model have certain applicability to settlement prediction of soft sub-grade. Based on the observational settlement data of soft sub-grade in an industrial zone, the features of Hyperbolic model and Logistic curve model are studied. By using curve fitting methods with Origin software to predict the sub-grade settlement value and analyze the simulation results, compare these two models to determine which one is more reasonable. The results show that the Logistic curve model is more accurate and reasonable, it has the value of popularization and application in engineering.

Abstract: Concrete blocks were arranged on both sides of the strip foundation to simulate overload. Model tests with overload or not were conducted, for four test programs including pure sand ground, single plate reinforced ground, double plates reinforced ground and single plate with two anchorage ends reinforced ground. The influence of overload on bearing capacity and settlement of ground, earth pressure and strain of FRP was analyzed. The test results showed that overload can enhance the bearing capacity, and reduce the ground settlement in a certain extent, with the beneficial effects of overload on reinforcement effect being decreased while the amount of reinforcement was increased.

Abstract: This article aims at assessing the influence of relative density on the hydraulic conductivity and shear strength of two sands, denominated S01 and S02, derived from different regions and formation processes. S01 is wind-blown and S2 alluvial. The results of characterization and hydraulic conductivity in constant head tests were presented for both samples. The results of direct shear tests with sand S01 prepared with 5 different void ratios were also presented, for a vertical stress of 100kPa. The S02 sample was prepared with 4 different void ratios and these underwent direct shear testing with vertical stresses of 25kPa and 150kPa. This sample was prepared with the maximum and minimum void ratio and submitted to strength tests at CD triaxial compression with confining stresses of 50kPa, 100kPa and 200kPa. Results showed that even with different grain sizes, and under different density conditions, there were no significant variations in the permeability of the materials. With respect to shear strength, sand S01 obtained higher angle of friction values than sand S02, even though the latter had a higher percent coarse fraction. Sand S02 was relatively similar in terms of friction angle values obtained in direct shear and triaxial compression strength tests.

Abstract: In conventional analysis methods of soil slope, we must presume potential sliding surface at first and then gain the safety factors, judge the stability of slope by the safety factors. In fact, if we know a slope is unstability but don’t know where will be slide or failure, we can’t adopt effective measures to support and prevent the sliding accidents appearing. This paper use RFPA-Centrifuge to numerical simulate the failure of soil slope with different support measures without presume any potential sliding surface, success to gain the failure process and the corresponding safety factors. From the calculate results of RFPA-Centrifuge, we can find where is the first failure point and all the slide mass. So if we can use good analysis software to simulate the failure process of slope and adopt corresponding support measures before the engineering beginning, the stability of slope will be better and the accidents will be disappeared or reduced.