Applied Mechanics and Materials Vols. 353-356

Abstract: Dynamic safety assessment of internal force of retaining wall is of great significance to ensure the safety construction of deep foundation pile, and the key is to get the actual bending moment. The curvature is acquired by curve fitting of retaining wall reformation with the least squared method, and the actual bending moment can be obtained by multiplying the curvature and retaining wall bending stiffness. This method overcomes the difficult that the actual bending moment cannot be directly measured, at the same time, the cost savings would be of great advantage. As the monitoring item of foundation pile which must be implemented, retaining wall deformation has sufficient data, which provide a solid foundation for the engineering application of back analysis of bending moment. This studied the safety assessment of bored pile retaining wall based on back analysis for bending moment and obtained some beneficial conclusions.

Abstract: Meso-fabric of gravel particles is not only a reflection of the unique sedimentary history, but also directly affects the geotechnical properties of moraine soil. However, there are few researches on it so far in geotechnical engineering field, due to the difficulty of obtaining undisturbed moraine soil sample. To change this situation, we succeeded in getting undisturbed moraine soil samples from the west side of the Yulong Snow Mountain with the delicate manual cutting work. We scaned the 6 pieces of moraine soil samples by CT instrument and obtained the real meso-fabric images of internal moraine soil for the first time. After CT images binarization and denoising processing with the help of Matlab, section fabric indexes of stone area ratio, grain orientation and particle shape of moraine soil gravel particles were described with conventional statistical methods. The results show that the differences between vertical sections are little, but the differences between vertical sections and horizontal sections are much more obvious.

Abstract: This paper introduces the empirical method of classifying soil layers with CPTU. Pore pressure dissipation test was taken in a certain soft clay field, according to the characteristics of penetration curve and the value of static point resistance, frictional resistance, friction-resistance ratio, soil horizon was divided. According to the characteristics of the pore pressure dissipation test curve of different depth, weak interlayers was further surveyed.

Abstract: The chambers of certain coal mine in Shandong such as central substation situate in soft rock which consists of mudstone and fine sandstone, etc. Obvious ground pressure behaviors, large deformation and failure of surrounding rock have serious effect on mine safety production, with the impact of various complicated deep large ground pressure. This paper presents a rational scheme to control the surrounding rock steadily, based on analysis of deformation and failure on large section soft rock chamber, combined with the concept of the" combined supporting technology of long and short anchors" and "the combined supporting technology of three anchors".

Abstract: The hydraulic filling is the construction method of joint way in Nanjing Second Yangze Bridge. The leaching facility, drainage time and cofferdam stability in filling are key points in design. By laboratory test, the compaction, direct shear and permeability test of different compaction are investigated. The deformation through field monitor is carried during the cofferdam construction and hydraulic filling. After parameter test and stability analysis according to hydraulic filling, it is shown that the drainage ditch in base of cofferdam can satisfy drainage requirement, the leaching time is about half of one month. The compactness of cofferdam is 0.92. The slope of cofferdam during construction and hydraulic filling is in stability by analysis. And the cofferdam is in stable situation during hydraulic filling according to deformation monitoring result.

Abstract: Slope failure is a kind of serious geologic disaster. This paper based on the detailed geology survey and analysis, judged the failure mode of the Pipayuan slope; Using ADINA which is professional finite element software, made mechanic calculation of slope, analyzed the stress condition and discussed the change of stress. According to the Strength Reduction Method, the slope stability safety coefficient was calculated. Results show that: the whole slope, may be slide along the soft interlayer, especially in the case in the event of heavy rainThe effectiveness is verified by the finite element calculation of slope with anti-slide pile reinforcement.

Abstract: The instability of rock mass in a large scale is caused by the geological interaction and movement over a long period of time, of which rock mass system cut by structural plane and free surface. Firstly the block theory and Kinematics vector analysis are applied to program the analysis of stability in rock mass slope in order to be fully utilised in the pragmatic constructions. Through Matlab compilation to calculate out the movable blocks then by DDA analysis method to analyse the movable blocks inconsecutively. The resultant force of rock blocks and strain can be solved to measure the stability of rock blocks according to the results.

Abstract: In order to study north China type coal field lower coal surrounding rock failure characteristics, a numerical model was built based on the numerical simulation software FLAC3D. Water inrush information was monitored during mining process based on optical fiber Bragg grating sensor technology. Lower coal surrounding failure characteristics were studied according to numerical simulation and monitoring results. This study show that the first weighting distance of the test face is from 35m to 40m and the periodic weighting step distance is from 10m to 20m. Coal floor can be divided to three areas which are increased stress area, decreased stress area and recovery stress area. Coal roof failure scope is like a composition of two saddle-shaped zones along trend and tendency directions. Normal failure depth of the test face floor is from 10m to 12.5m, and it can reach 22.5m near open-off cut and stop line. The research can explain the reason of the test faces water inrush accident and can direct lower coal mine water control work.

Abstract: Aiming to improve the calculation result of the total settlement of soft ground of seawall engineering in design, one seawall engineering case is enumerated, and the changes in the thickness of compressible stratum and the primary consolidation settlement are studied by considering the settlement as filling load. The results indicate that the thickness of compressible stratum is increased and the growth of the primary consolidation settlement is about 30% in contrast with the primary consolidation settlement only considering the design load. At last, this paper suggests that a designer should weaken the weight of settlement correction coefficient instead of strengthening the settlement as filling load in future design.

Abstract: A dam site, whose main rock is celadon clay rock, has an obvious time-efficient behavior in the respect of displacement and mechanics from the field observation. This feature has a certain effect to the safety of the dam site. In order to simulate the characteristic of time dependency of this rock with numerical method, this paper first use the monitoring data of test hole to determine the constitutive model, then the rock mechanics parameters were obtained by back analysis method. The results show that there is a good consistency between numerical modeling and field monitoring. This achievement can be used to analysis the stability of project dam.