Abstract:

Abstract:A new tiecolumn such as corecolumn, named as coretiecolumn, for the substitution of castinplace tiecolumn was used to improve seismic performance of mansonry structures. Pseudostatic testes of 11 wall specimens including 6 walls constrained by coretiecolumns, 2 walls constrained by castinplace tiecolumns, and 3 walls without constraints were carried out to study the seismic deformation capacity of mansonry walls with coretiecolumns. The skeleton loaddisplacement curves and the normalized skeleton curves, displacement ductility factors，drift angels of the specimens were analyzed and compared. The effects of the level of vertical compress load, aspect ratio and the wall style on the deformation capacity of the wall with coretiecolumns were distinguished. It is shown that the constraints effects of coretiecolumns on masonry wall are effective and the walls with coretiecolumns have good deformation capacity as those with castinplace tiecolumns.

Abstract:A finite element method considering interaction betwee bending and shear lag deformation was proposed and the finite element formulations including the effect of shear lag was deduced. The effect of shear lag on structural behaviours in indeterminate boxgirders was studied in detail based on the proposed method. Firstly, the shear lag effects on deflection and the shear lag coefficients were analyzed for both determinate and indeterminate beams. The results obtained by using the proposed method were compared with those by using the analytical method. Finally, the effect of shear lag on redistribution of internal forces including shear force, bending moment, and additional bending moment due to shear lag in indeterminate boxgirder bridges was studied. It is found that the effects of shear lag on deflection and stresses at a crosssection are obvious for both determinate and indeterminate beams, while the effect of shear lag on internal forces in indeterminate boxgirder bridges is small and may be neglected.

Abstract:A parametric analysis was carried out to investigate the gusset plate to CHS XXjoints with the finite elements method. The effects of web loading proportion, geometric parameters and axial stress in chord on the failure modes and the ultimate strength were employed. It is found that the web loading proportion have different effects on the ultimate strength with different angles between two gussets. And the ultimate strength of joints decreased no matter the axial stress in chord was positive or negative. Based on the regression analysis, a formula was proposed for predicting the ultimate strength of the gusset plate to CHS XXjoints.

Abstract:Windinduced responses of a single steel circular antenna with an asymmetric brace were computed considering wind speed and direction joint distribution function at location of the structure, and then windinduced fatigue life of the structure was estimated in frequency domain and time domain, respectively. Some parameters, including wind direction, surface roughness, vortexinduced resonance and mean wind speed, which would have effects on the windinduced fatigue life of the structure,were discussed. It is found that 1) wind direction has great effects on windinduced fatigue damage, that is, significant fatigue can occur in wind direction of high probability; 2) the more roughness the surface of structure is, the shorter the windinduced fatigue life is; 3) the effects of vortex resonance on windinduced fatigue life should not be neglected; 4) the mean velocity has slight impact on the windinduced fatigue life of the structure.

Abstract:A method was developed for nonlinear analysis of laterally loaded long piles in cohesionless soil. It is considered that the modulus of horizontal subgrade reaction is related with groundline pile displacement by an attenuation power function based on the existing methods and it is assumed that both the modulus of horizontal subgrade reaction and the ultimate soil resistance increase linearly with depth . It is also considered that soil in front of the pile may change from elastic state into plastic state as pile displacement increase. Nonlinear differential equations of the fourth order were derived for both states and to solve the equations, the Gleser finite difference approach with iteration and the ReeseMatlock approach were developed,respectively of propsed methed. It is validated by the test and numerical field calculation that the results respectively of proposed methed are more accurate than ‘m’method and simpler than ‘py’method. And the results are in good agreement both when pile displacement is small and large,thus it can be applied to construction in place of ‘py’ method especially when test parameters are unavailable.

Abstract:The uniaxial creep tests were carried out for deep limestone from Chongqing adoptal by the MTS815 servocontrolled rock mechanical test system. Meanwhile, the DISP2 based AE system was used to test acoustic emission (AE) signal. It is found that AE can better reflect rock microstructure such as diffusion of lattice defects, opening and close of the pore and fracture, compatible deformation among particles, the generation and connection of micro ruptures. Through different creep model parameter inversion, 〖JP2〗it is concluded that either the logarithmic function creep model or the exponential function can better reflect deep rock creep deformation behavior and the logarithmic function creep model is much better. 〖JP〗

Abstract:It is a fundamental task for soil structure study to find a quantitative parameter that reflects structural damage under pressure. Based on the unidirectional compression and isotonic compression tests of soft clays from Huangshi, Zhangzhou and Qingdao, the compression properties of structure soil and the effect of different conditions on the properties were investigated. It is found that when the pressure is lower than structure yield stress, it is mainly the initial structure selfalignment procedure and the structure is in few damage and the compressibility is small. When the pressure is bigger than the structure yield pressure, the structure destroys massively and the compressibility increases greatly not only from intergranular slipping but also from the collapse. With the damage properties in compression, a new coefficient was proposed to evaluate the structural behavior. And this parameter can be obtained simply through the software AutoCAD. With the proposed method, it is found that the soft clay in Qingdao is strongest in structural behavior, followed with that in Huangshi and Zhangzhou.

Abstract:Different kinds of structures of RAP and different contents of cement were prepared. By means of standard compaction test, unconfined compressive strength, water stability, modulus and SEM test, the cementation effect with cement was studied. It was shown that the maximum dry density of RAP mixture rose from 1.91g/cm3 to 2.00g/cm3 with the increase of cement content when A/S was 0.4. The maximum dry density of RAP mixture would rise when adding more asphalt. The unconfined compressive strength rose from 1.48MPa to 2.63 MPa and then down to 2.28MPa when cement content was 6%. The best property could be got when A/S was 0.4 and the cement content was 6% with 9.5% water. The compressive strength of RAP mixture declined after it was cured in water for 24 h, but it had the same tendency with those of which had not been maintained in water. And it is also found that RAP does not obtain better stabilities in high temperature with modular test. From SEM test, it is shown that ettringite and CSH interlace and form the netted structure, and the aggregate would be enwrapped to increase the strength.

Abstract:The cold inplace reclaimed composite base technique is a technique that the partially old asphalt pavement and the partially old base was milled together then reclaimed inplace as a new base with flexible and rigid property. Taking the treatment project for failed asphalt pavement of Yuhu Expressway in Chongqing as a case study, the structure thickness and the structure composition, the material parameters, the technological parameters were studied and mechanic behavior was discussed for the cold inplace reclaimed composite base. It is found that (1)based on milling and reclaiming asphalt concrete with upbase stabilized by cement together, a suitable compacted thickness should be controlled within the 26cm to ensure the compaction quality for the cold inplace reclaimed composite base,;(2)the void contents for the cold reclaimed composite base would be restricted at low than 12%;(3)a waterproof layer should be set and the thickness of new asphalt concrete should be paved to be more than 9cm on the cold inplace reclaimed composite base;(4)the principal technical performances are recommended using the Marshall Flow(to be controlled in the range of the 3～5 mm)、soaked split strength(to be large than 0.45 MPa)、the freezethaw split strength ratio(to be large than50%) and the bend strain( to be large than 1 800 με) as the controlled index of the cold reclaimed composite base. And the dynamic stability(to be large than 2000 times/mm)only is used as a secondary technical performance.

Abstract:Scientific method was necessary for road decisionmaker to select high costeffect ratio pavement structure scheme. According to the fact that many uncertain knowledge and information existed in the process of evaluating the expressway asphaltpavement structure schemes， an evaluation model of pavement structure schemes based on uncertainty measurement was put forward;This method implemented ordered division of assessment space，and could recognize and rank different schemes by comprehensive measurement matrix of multiple indexes. three typical design programs of expressway asphalt pavement structure were evaluated by that model.It is shown that the assessment can objectively reflect the comprehensive performance of asphalt pavement structure ，which provides a new method and way for evaluation of pavement structure schemes.

Abstract:The temperature of water used for surface water source heat pump（WSHP） could make dynamic changes in the condition of heat or cold rejection. When the water temperature is over the amount of heat or cold rejection that water can take, WSHP system will run irregularly even paralyze. Based on twodimensional model of the initial water temperature, dynamic model of water used for WSHP was proposed with mass equation and energy equation. And with flow equation coupled with temperature equation, the equation of water temperature changes in load was obtained.

Abstract:Particle deposition in a fully developed turbulent flow of ventilation duct with a rectangular cross section of 0.3 m×0.2 m and 3 m in length was investigated. The effects of thermophoretic force and air humidity were also considered. Trajectories of 3 000 particles were tracked on the basis of the random walk model from Lagrangian approach. The profile of dimensionless deposition velocity with relaxation time was achieved and the comparison with the previous studies was made with particle size range of 0.0150 μm and air flow velocity of 5 m/s. It is found that the trend of dimensionless deposition velocity is in agreement with the previous studies and the profile of dimensionless deposition velocity showed a Vshaped curve. The effects of temperature and air humidity were also investigated with particle size of 1 μm. Thermophoretic force caused by temperature gradient between air flow and wall surface accelerated particle deposition. Meanwhile, it is also found that the deposition velocity increases with the increase of air relative humidity.

Abstract:Based on the raw of moisture absorption under humid environment in hothumid area, the balance method was adopted to measure the moisture absorption and desorption curve of thermal insulation glazed hollow bead motar in the natural condition. And wind tunnel hothumid climatic was adopted to measure its moisture content of quality equilibrium. And then guarded hot plate apparatus was employed to measure and analyze its thermal conductivity in moisture equilibrium condition. It is found that : 1) the moisture content of quality equilibrium of thermal insulation glazed hollow bead motar under humid climate in southern area is about 3.55%; 2) under the moisture equilibrium condition, the correction factor for thermal conductivity of thermal insulation glazed hollow bead motar is from 1.04 to 1.11 and with the mean of 1.08, and it is recommended to be 1.10 considering the complexity of moisture absorption during the process of building energy efficiency design for practical projects.

Abstract:Steadystate heat transfer performance is an important indicator for wood wall to assess its energy efficiency performance. Based on the introduction of foreign advanced technology of wood residence, 13 different wall specimens were manufactured using domestic materials in this study, and the effective heat transfer coefficient were measured by hot boxheat flow meter test method. With the results from theoretical calculation, it was found that the effective heat transfer coefficient of walls were between 0.226～0.529 W/(m2· K). The thermal level was IIt for specimen 1,2,3, and 6, and level It was for the others, which could be appropriate for the severe cold areas and meet the requirements of 65% Energy efficiency standard in China. The calculation results were in good agreement with the measured ones.

Abstract:Roof planting is widely recognized as a ecological thermal insulation for roof. A lightweight green roof in climatic conditions of shanghai was investigated as a case study by applying PMV index to calculate thermal comfort compared with that with traditional roof in air conditioning. It is found that the PMV value of green roof is 0.2 lower than that of traditional roof, while the fluctuating range of green roof was only 1/4 of that of traditional roof. And the equivalent thermal insulating roof of green roof was obtained by computing. Furthermore, it is shown that green roof has lower interior surface temperature than equivalent insulating roof in the condition of higher indoor temperature.

Abstract:The influence of luminance level on students’ productivity, asthenopia (an eye strain), and brainfag (a mental exhaustion and depressive disorder) was studied with three typical colour temperatures of T5 fluorescent lamps. The changing rate of productivity and asthenopia were measured by using anomalistic distance determination and Анфимов alphabet test method and the changing rate of productivity was regarded as the brainfag index. It is found that medium colour temperature fluorescent lamps with appropriate exposure time can produce desirable consequences, stimulate the subjects’ cognitive ability and enhance their productivity. However, some lamps with lower or higher colour temperature produced undesirable consequences. The optimal luminances levels were thus variable and correspond to the colour temperature of lamps. The worst combination of colour temperature & luminance was identifies and should be avoided in classroom lighting design.

Abstract:By combining the membrane bioreactor of the PVDF hollow fiber membrane with the A/A/O process, a pilot test system of A/A/Omembrane process (A/A/OMBR) was constructed and employed in treating municipal wastewater in Taihu Lake Basin. According to the nitrogen removal of combined process, the nitrification rate of activated sludge in MBR was studied. The effect of dissolved oxygen concentration, influent ammonia nitrogen concentration and temperature on nitrification rate was analyzed. It is found that the average removal rates of ammonia nitrogen of combined process are 96.56% and 96.68% in summer and winter, respectively. Influent ammonia concentration has little effect on nitrification rate at low temperature of less than 15.0 ℃. Higher temperatures would speed up the nitrification rate and the nitrification rate of combined process at 30.5 ℃ was 2.6 times than that at 11.8 ℃. Compared with the conventional process, nitrification rate of combined process was 2.3 times than that in oxidation ditch. The enhanced nitrification of long hydraulic retention time formed by two nitrification phase and the role of membrane filtration in MBR offset the inhibitory effects of low temperature on nitrification rate.

Abstract:The removal effect of dissolved organic matter（DOM）in landfill leachate by FentonSBR treatment process was investigated. And the changes of DOM molecular weight (MW) and the fractions humic acid (HA), fulvic acid (FA) and hydrophilic (HyI) in combined process was also analyzed. It is shown that the removal of COD 、DOC and UV254 was 79.1% 、73.6% and 92.9% with the combined process, respectively. The removal of COD was above 80% except for those with the molecular of 10～4 ku. The removal order of DOM fractions and three index of each fraction was HA>FA>HyI and UV254>COD>DOC, respectively.

Abstract:Orthogonal experiments were carried out for high grade gray water treated by combinational technique of coagulation sedimentation and constructed wetland. With the orthogonal experiment of coagulation sedimentation pretreatment, it is shown that the regression equations relating to effluent BOD5, cubage loads(Nv), temperature(T) and PAC addition dosage(ρ) is BOD5=2.05Nv-0.41T-0.82ρ+38.9. For the orthogonal experiment of constructed wetland posttreatment, it is shown that the regression equations relating to effluent BOD5, cubage loads(NA), and temperature(T) is BOD5=1 190 NA-0.32T+12.2. Based on the two orthogonal regression equations, combined with reclaimed water quantity requirements in different seasons in buildings, an investment optimization model of combinational technique was established. According to the model, the reasonable scale of the reclaimed water treatment systems can be determined and treatment efficacy can be well predicted.

Abstract:Potassium ferrate (Fe(VI)) was prepared by using purified sodium hypochlorite solution, iron(III) nitrate, potassium hydroxide. The removal performance of the tetracycline hydrochloride (TC) in water by using potassium ferrate was investigated. The effects of dosage of ferrate, pH value, oxidizing time on the removal rate of TC were studied. It is found that the optimal pH value range for TC degradation is 9~10, and TC could be removed by ferrate efficiently and quickly. The removal efficiency of TC and reaction rate were increased with lager dose of ferrate. The major degradation of TC occurred during the first 60s, followed by further degradation over next 10~20 min. At Fe(VI)∶TC molar ratios of 1∶1 and 1∶5, approximately 100 % of the TC was removed after 60 s. Only a small reduction of TC occurred in spite of quick conversion of TC, implicating that a majority of TC transformed into intermediate products without complete mineralization.

Abstract:The effect of temperature on nutrient removal performance and operation cost with DO control by frequency conversion was investigated during the longterm operation process of treating realistic domestic wastewater with pilotscale SBR process. It is found that the temperature has limited influence on the removal efficiency of COD and PO43-P, while has obvious impact on ammonia removal. Ammonia oxidation rate decreased sharply with the decrease of temperature when the temperature was from 11 to 26℃. Meanwhile, phosphorous uptake and release rate of microorganism almost fixed at normal level under temperature (1826℃) and decreased sharply at temperature (1118℃). Finally, the variation of energy consumption at different temperature was investigated. And the effect of DO control by frequency conversion on the energy consumption of aeration phase was analyzed.

Abstract:The stabilization properties of agedrefuse in fiveyearold semiaerobic and anaerobic landfills were compared, such as volatile solid (VS), total organic carbon content (TOC), humic matters, and so on. It was found that VS and TOC content in agedrefuse were obviously lower than those in fresh refuse after five years disposal. However, the VS and TOC content of agedrefuse in semiaerobic landfill were slightly lower than anaerobic ones, whilst the difference was not significant. Surface settlements of semiaerobic landfills were higher than that of anaerobic ones (P<0.05). Moreover, there was negative correlation between VS content and surface settlements. Both leachate and water recycling methods did not lead to significant VS content difference, while leachate recycling would cause obviously uneven surface settlement. Biological degradable materials (BDM) value of agedrefuse in semiaerobic landfill and anaerobic one was similar. Furthermore, BDM value increased with the increase of air pipe distance and depth. The greater the air pipe distance is, the bigger the difference of BDM value between the layers is. In addition, total extraction ratios of humic matters and HA/FA in semiaerobic and anaerobic landfill agedrefuse had no significant differences.

Abstract:At first, the influence of recycled coarse and fine aggregate on dry shrinkage features of concrete was studied. It is indicated that the recycled aggregate makes significant impact on dry shrinkage features of concrete, particularly the fine aggregate. Through the optimization of the mix of recycled highstrength concrete, the dry shrinkage rate of coarse aggregate concrete was only slightly larger than that of the natural one. Bulking agent used in recycled concrete could compensate the shrinkage effectively to achieve the objective of microshrinkage. At the same time, it is shown that the impact of conservation in dry environment on recycled concrete strength is greater than that of ordinary one. Thus, more attention should be paid to the moisture in the conservation of recycled concrete. In addition, the shrinkage mechanism of recycled concrete was analyzed from the perspectives of interface structure and aggregate features.〖JP〗

Abstract:Taking the split Hopkinson pressure bar(SHPB) test data as training samples, an implicit dynamic constitutive model of steel fiber reinforced concrete(SFRC) was proposed with the improved BP neural network program. On the basis of ABAQUS/Explicit, a userdefined material subroutine VUMAT was compiled with FORTRAN language, embedding with the neural network constitutive model into finite element calculation. With SFRC structure＇s response under impact load as case study, it is shown that the constructed constitutive model and its finite element method are effective.

Abstract:The fatigue resistance of Gussasphalt mixture was analyzed with energy method after fourpoint flexural fatigue test under multiple strain levels. Through the fatigue test under multiple strain levels, the linear relationship was obtained between fatigue life and cumulative dissipated energy in loglog plot. And the equation for fatigue life prediction under different strain levels was also regressed. Besides, the relation between fatigue damage and dissipated energy of Gussasphalt mixture was analyzed with Maxwell model. And with the conceptions of hysteresis loop and phase angle, it is found that the mixture with bigger phase angle has better fatigue resistance.