Advanced Materials Research Vols. 639-640

Abstract: As for those high piers of bridge that constructed crossing sea and clough, the p-delta effect is evident; Looking upon present situation over the domestic and foreign research, stipulated laws on p-delta effect are various. Research shows that computing upper pier displacement by energy method was simple and versatile for different load case in comparing with other methods, and neglecting p-delta effect often underestimated the disadvantageous state when the pier is high; also, lateral loads like wind and seismic force further aggravate the pier state.

Abstract: Considering the movement effect of translation mode，friction angle reduction coefficient and method of bevel-layer analysis,estimation of active earth pressures is deduced for cohesiveless soil retaining wall with translation mode.In order to validate the feasibility of the proposed approach，a model test for active earth pressures was conducted in laboratory;and the proposed method was used to analyze this model. Experimental and theoretical results indicate that the curve of active earth pressure increases firstly and decreases then along the depth of retaining wall with different values of s/sc,and it has a point of intersection with the curve of Coulomb active earth pressure at the depth of 0.6H，where H is the wall height. Further study indicates that the action point position of the active earth pressure is higher than 1/3 times wall height.

Abstract: This paper introduced construction method for deep pile of Zishui bridge through karst region and the checking results of the pile bearing capacity. Firstly, main structure of Zishui bridge was simply introduced. Secondly, according to the special geological conditions, construction methods for bored piles in water and drilling platform were described. The discussion focused on the problem of boring and grouting in karst foundation and their solutions. Finally, to ensure that the pile capacity can meet the design requirements, load transfer method was used on the part of pile foundation to calculate the bearing capacity. Results showed that pile bearing capacity meet the requirements, and the feasibility and correctness of construction method of Zishui bridge was also verified,which provides references for the design and construction of the same civil engineering.

Abstract: The geological model of pit of binary structure stratum is established under the analysis of the engineering geological characteristics of the binary structure stratum of Wuhan , combined with land subsidence and groundwater flow characteristics calculated. Associated with the use of software of Processing Modflow to calculate settlement around the excavation, the rules of ground settlement of excavation of dual structure stratum in Wuhan are obtained. And it provides a theoretical foundation and practical support for the same project.

Abstract: In this paper, we studied mechanics characteristic of whole weathered granite improved soil. We analysesed its changes of fluid plasticity index before and after improvement in different compaction condition. We improved the full weathering granite by adding different proportion of lime and cement. We analysised the changes of liquid limit and plastic limit of improved soil in the different mixed ratio condition and we got the conclusion that the improved soil plasticity index decreased with lime or cement dosage increases, also changed over time. Improved soil liquid limit, plastic limit and plasticity index changed with the addition of lime, cement dosage changes exponentially.

Abstract: Energy transfer of pile body in foundation is considered by the energy balance equation of pile unit. Bilinear model is used to calculate the pile side load transfer, and trilinear model to calculate the toe resistance load transfer. According to the deformation coordinating relations, pile load-settlement curve analysis method is obtained. Comparing the in-situ and calculation data, the results show that they are basically consistent. The conclusions are pile bearing properties can be analyzed reasonably by this method, and the calculation results can provide a reference to engineering practice.

Abstract: The paper focuses on the development of a cyclic plasticity model based on the fuzzy set theory, which is implemented as a computational tool in order to simplify the computer programming of the constitutive driver. The constitutive model is a rate independent elasto-plastic model which is capable of describing repeated load cycles, dilatancy, material memory, and critical state soil mechanics features. Also, with the aid of membership function, the validity of the constitutive model is enhanced by comparing the theoretical output with a set of experimental data obtained from a variety of cyclic triaxial tests of loose sand.

Abstract: Based on meeting the requirement of ground bearing capacity, the allowable range of anti-overturning safety factor is derived. The relative parameters are expressed with base width and the relation graphs of conversion factor are presented, and then can design the cross-section of retaining wall directly by combining the stability requirement of anti-sliding. The calculated result shows that this method makes the design simple and reliable. It may be a reference for engineers.

Abstract: Based on the fundamentals of heat and moisture transfer in porous media, characteristics of heat transfer intensity of a bamboo structure wall are analyzed when the moisture content changes under the action of natural warm and humid environment. The results show that: when the moisture content changes, the effective coefficient of heat conductivity and specific heat capacity of bamboo both change, and physical parameters (e.g., heat transfer capacity, heat storage capacity, temperature distribution, attenuation coefficient of temperature wave, delay coefficient of temperature wave) all change accordingly. When the total moisture content of the wall increases, the temperature difference between inside and outside surfaces of the wall is reduced, and attenuation and delay coefficient of temperature wave both increase. All of these improve the thermal comfort of indoor environment, but the heat transfer capacity through the wall increases. If the total moisture content of the wall is constant and the moisture distribution along the thickness direction of the wall changes, the temperature gradient decreases and the heat storage coefficient increases in bamboo layer of high moisture content, and the temperature gradient increases and the heat storage coefficient decreases in bamboo layer of low moisture content.

Abstract: In order to investigate the explosion resistance performance of perforated masonry walls strengthened with polyurethane, nine numerical models with different layer number and different strip width of polyurethane are established in this paper. Deformation drawings and time history curves of displacement of the numerical models are comparatively analyzed. It is found that there are two failure modes, global failure and local failure, of strengthened masonry walls and the differences of failure patterns are significant between various types of strengthening method.