Abstract:

Abstract:Differential weathering overhanging rock by hard rock and soft rock interlayer is common for geological failure.To study the influence of ground stress in rock slope and cave deepness to differential weathering overhanging rock,a mechanical model was proposed.And hollow cylinder stress meter was used to test and analyze onsite ground stress at Hongyadong in Chongqing.Moreover, the development range of overhanging rock was determined.And a case studywas used to analyze the relationship among tension ground stress, cave deepness and growth of controlling crack.A method for forecasting overhanging rock failure pattern was proposed.

Abstract:A number of lands were occupied by discarding the dredged sludge in the yard as waste materials.The Aeration Vacuum rapid MudWater Separating (AVMWS) technique was appropriate for discarding yard with high water content and high clay particle content sludge.This technique could quickly reduce the volume of the sludge and accelerate the turnover use of the yard.In addition,the technique could overcome the clogging problem when pumping water from high watercontent, high clay particle content dredged sludge.Through the sampling particle size distribution tests after AVMWS and conventional vacuum pumping model tests, it was found that in the AVMWS tests the finegrained soil run off, coarse particles accumulated, and arching structure layer was formed.However, in the conventional vacuum pumping tests, fine particles did not lost and there was clogging without arching structure layer.The layer could protect the internal loss of the fine particles and ensure a high permeability of the soil at the same time.And the mechanism was explained as well.

Abstract:By the law of conservation of mass, onedimensional municipal solid waste(MSW) degradation model was proposed with considering the degradation and density fluctuation, the relationship between density, quality and volume and the degradation characteristics obtained from the degradation test.With the analysis, it was found that the settlement of degradation was positive proportional with the following three elements: the volume percentage of organic matter, the rate of degradation and the initial height.As a case study, the degradation settlement of Chongqing MSW landfill was predicted.And it was found that the relationship between the settlement and the time showed exponential attenuation trend, in which the degradation settlement of MSW landfill was large in the initial stages, and then it gradually stabilized with the time.

Abstract:In order to discuss the deformation characteristics of rock mass under different water levels changing between 145 and 175 meter in the Three Gorges reservoir area, an experiment was carried out for the studying sandstone deformation under the conditions of three different axial stresses(σ1=55.54,34.18,12.82 MPa), two cyclic pore pressures(Pmin=2 MPa,Pmax=6 MPa) and two kinds of constant time(the upper limit time and the lower limit time(ΔT=120,240 s).With ε1-T curves and p-T curves, as well as p-ε1  hysteresis curves, it was found that the curves were continuous sine wave-shaped curves.At first, the strain decreased with loading pore pressure.And then, it decreased to valley value with pore pressure at stable upper limit.Next, it increased with unloading pore pressure and increased to peak value with pore pressure at stable lower limit.The p-ε1  hysteresis curves of the sandstone had two typical stages.And one was caused by the closure of some primary pores and crack under increasing compaction, in which the strain did not form obviously hysteresis curves, and the other was pore pressure coupling stage which showed obvious hysteresis curve in form of the anti-clockwise from the dispersed to the dense.In addition, Δε-n curves in four sections (loading, unloading, steady upper limit, steady lower limit) of p-ε1 curves were compared and respectively ananlyzed in the condition of various axial stress and different constant time .

Abstract:On the condition of constant temperature, grouping drywet soil with different initial water content and different time intervals, the experiments were carried out to study vaporous transfer, vaporousliquid transfer and the relationship of unsaturated expansive soil.And it was found that the soil behavior, water content and water content gradient were pivots for the transfer.Vaporous transfer, vaporousliquid transfer were increased with the increase of moisture gradient in a complex nonlinear relationship with times and locations.And with the less water, the adsorption capacity of soil was strong, resulting in larger gradient of moisture.While for larger water content, free water was more with more even of the moisture.

Abstract:Since there are the root systems of herbaceous plant in the shallow layer of soil masses of slope, the shallow layer of slope becomes a compound materials made of soil masses and root system.Owing to friction action and tensile resistance action of roots, the shear strength of soil layer with root system is increased.And a comprehensive mechanical analysis of how herbaceous plants strengthen slope was carried out.Not only a mechanical model of interaction between root and soil, but also a quantitative calculation of increase of shear strength and stability coefficient of slope was put forward.As a result, the theoretical basis of herbaceous plant ecological slope protection was provided.

Abstract:When tunnels are through waterbearing section of fractured rock mass, a complex interaction process between rock mass deformation and fluid transportation is one of the most important reasons for water gushing, water bursting and mud bursting.To study the rock mass deformation and fluid transportation in tunnel excavation under complex geological conditions, a hydraulic model of complex crack rock mass was established from the relationship between the crack growth degree of surrounding rock in deep buried tunnel and the engineering scale, with which fracture network of different levels in rock mass could be considered simultaneously.Furthermore,a computer Fortran program was put forward to simulate the solidfluid coupling of excavation process of a deep buried tunnel.And it was found that the principal fractures had strong flowing action and network fractures had storage function and lag effect in seepage area.And the yield area of surrounding rock was increased under the coupling of seepage field and stress field.

Abstract:Height of similar rockmass landslides in one tunnel section was processed with the statistical method in the existing design codes.However, the spatial variability within the similar rockmass length was not taken into account.In order to overcome the shortcomings, an equivalent deviation increasing function of the space rockmass landslides height σh(L) was put forward.And the WeibullБοлοгин statistical theory for brittle materials failure was employed to find the equivalent compressive strength of tunnel secondary lining with different concrete volumes.As a result, the problem of space structural system reliability for the deepburied tunnel could be simplified as a plane problem.Taking the class Ⅲ deepburied rockmass in Jinzhou tunnel as an example, the characteristic values of joint spacing, variance upper limit of rockmass landslides height and the length of the tunnel to affect the system reliability were analyzed.And it was shown that the system reliability index increased with the increase of characteristic values.The system reliability index decreased gradually with the increase of variance upper limit of rockmass landslides height and the length of the tunnel.However, the reliability index would be towards a stable value at the end.

Abstract:Because of the existence of initial hydraulic gradient in clay, nonDarcy equation with initial hydraulic gradient was modified with classical consolidation theories of sanddrained ground.And the approximate solution in the instance of vacuum preloading was presented.Based on this, the effect of initial hydraulic gradient on the seepage front, the pore water pressure and the average degree of consolidation were investigated.It was found that the spread of vacuum pressure was delayed because of initial hydraulic gradient, resulting in the dissipation of pore water pressure and the speed of soil layer consolidation.The hysteresis became more and more evident with the increase of initial hydraulic gradient.In addition, initial hydraulic gradient also caused some residual pore water pressure which could not reach vacuum pressure.Thus, the ultimate average degree of consolidation was less than 100%, which decreased with the increase of initial hydraulic gradient.

Abstract:Using the computer program of SAFIR, the influences of some parameters (i.e., axial/rotational restraint ratio, sectional dimension, load ratio, load eccentricity ratio, reinforcement ratio, and heating time, etc.) were analyzed on axial forces in restrained concrete columns exposed to ISO834 standard fire with cooling phase, compared with those in the standard fire without cooling phase.Based on the simulation results of 2880 cases, a practical calculation method for axial force in column was proposed.It was shown that: (a) for axiallyandrotationally restrained columns in fire with or without cooling phase, the enhancement coefficient of axial force increased gradually first, and then reduced gently or kept constant, and finally decreased quickly.However, in the late stage, the enhancement coefficient corresponding to fire without cooling phase dropped more significant than that with cooling phase; and (b) the influences of the rotational restraint ratio, column length and thickness of concrete cover on the enhancement coefficient of axial force in axiallyandrotationally restrained columns were limited subjected to fire with cooling phase, while the peak value of the enhancement coefficient increased with the increase of the axial restraint ratio, load eccentricity ratio and reinforcement ratio or with the decrease of the load ratio and sectional dimension.

Abstract:To deal with the contradiction between accuracy and time consuming, a model of reliability analysis of CFT was proposed based on the response surface and nonlinear finite element method, And Initial geometric imperfection was induced by consistent mode imperfection method.The reliability index and sensitivity coefficients of CFT high piers were invested by the proposed model.The effects of slenderness, eccentricity and diameterthickness ratio on reliability index of concretefilled tube high piers were studied by parameter analysis method.Meanwhile, the influence of geometric nonlinearity was also analyzed and the reliability of CFT high pier could be affected by factors mentioned above.Based on the analysis, several suggestions for improving the reliability of CFT high piers were proposed.

Abstract:A numerical simulation test of the internal explosive loading on largespace structure was carried out by employing algorithm ANSYS/LSDYNA.An appropriate model was established for calculating the dynamic responses of the largespace cylindrical reticulated shell under innerblast loading based on the proof of correctness and reliability of the model and parameters selection.Combining the Ritz vibration mode superposition method with the Proper Orthogonal Decomposition (POD) method, the problems of spatiotemporal asynchrony of shock waveforms and pressure distributions on largespace structure surface were solved and the calculation for dynamic response of largespace structure was reduced and simplified.Furthermore, the numerical simulation of dynamic responses was carried out.And the influence of the ratio of rise to span and the explosive position on the dynamic responses of the structure was studied.It was found that the calculation model was suitable for the dynamic response analysis of the largespace cylindrical reticulated shell under internal explosion and the cylindrical reticulated shells with bigger ratios of rise to span were stronger in the capacity of antiexplosion.In general, the damages to the largespace structure caused by eccentric blast shock waves were more serious than that caused by central explosion.And it was the most disadvantageous to the edge components of the structure.The more attention should be paid to the antiexplosion capacity of the support areas and the edge components while designing the shells.

Abstract:Aiming at the effect of permeable pavement, especially on hydrology and thermology, a longterm monitoring was carried on the site for half a year to know how the permeable pavement works in rainstorm runoff suppression under ground water taking, and how the temperature of the ground surface drops, as well as the duration of temperature decrease.It was found that when the amount of rainfall on the rain field was smaller than 35mm, the infiltration efficiency went up to 80% and above.As for thermology, the temperature of permeable pavement decreased continually for two days under the temperature of 19~23℃.

Abstract:The experimental task was very large for solving fremitus derivative of bridge by free vibration method proposed by R.H.Scanlan.And in the process of extracting cross derivative, it was difficult that the frequency ratio and damping ratio under vertical motion and torsional motion were kept the same in all wind speed.Besides, the discriminating error of uncoupled derivative would be coupled in derivative.Considering these, an improved method based on Modified Ibrahim Timedomain Method was proposed.With the application, it was found that this method was better than least square method.

Abstract:Based on the refined threedimensional modeling method, a coupled vibration FEA(finite element analysis) model was established for light railway train and long span twolayer cablestayed bridge with the consideration of the material and geometry nonlinearity and over 2.2 million of element and nodes.To overcome the computing difficulty for large number of element, the solution was carried out with the Dawning 4000A supercomputer in Shanghai Supercomputer Center based on Contact Balance Bisection Algorithm for parallel computing.Through the simulation of one way and two way conditions, the key component's stress of cablestayed bridge girders and dynamic response of middle span section was respectively analyzed.

Abstract:Energy consumption and thermal parameters of green roof and bare roof were measured in the airconditioned and nature indoor environment in summer.It was found that the heat flow of green roof was reduced about 70%, and additional equivalent thermal resistance of green roof was about 1.0 m2·K/W in the airconditioned,cooling efficiency of green roof was about 111% in the nature condition.

Abstract:Based on Fourier and Fick law, a modified Budaiwi model considering phase change within wall and the effect of solar radiation was established by using air humidity ratio in wall and temperature as the driving potentials.The term omitted in the mass transfer equation of the original model was added in the modified model.To evaluate the accuracy of the model, a test system was set up to measure relative humidity and temperature within a porous wall under actual weather conditions and compared with the prediction of the model.It was found that the predictions were in good agreement with the experimental results.At the interface close to outdoor, the average deviation of the relative humidity was 4.44% and average temperature deviation was 1.31K.At the interface close to indoor, the average deviation of the relative humidity was 6.3% and average temperature deviation was 1.26K.

Abstract:To improve organic pollutant degradability of landfill leachate, culture medium was prepared with landfill leachate and agar.And then three functional bacteria were cultured and screened from sludge in aeration pool of biochemical treatment system by bioaugmentation.Based on 16S rDNA identification, these bacteria were named Marinobacter (coded Y1), Acinetobacter (coded Y2) and Escherichia (coded Y3).Functional bacteria were scaling up, and then inoculated into biologicalactivated carbon (BAC) reactor by physical circle absorption method.With the control experiment, it was shown that the natural startup BAC had significant degradation capacity to organic pollutants with molecular weight M of 10 ~ 5 kDa.And the inoculums' startup BAC with functional bacteria was kept with was with removal rate of 76.1% for organic pollutants with molecular weight M of 100 ~ 30 kDa, and 80.9% for organic pollutants with molecular weight M exceeding 100 kDa.

Abstract:As the increasingly serious contamination of source water as well as the more stringent water quality standard, the pretreatment and advanced treatment were required for water supply enterprises.To find an appropriate treatment, the traditional approach is normally based on experts' knowledge and their experience which has several shortcomings.In order to find an effective and efficient way coping with the issue during selecting the optimal technologies for water treatments, an improved analysis hierarchy and fuzzy evaluation model was proposed.With the model, multistage fuzzy synthetic judgment was adopted with the Improved Analysis Hierarchy amended by Accelerating Genetic Algorithm.The application of this model had been introduced for the selection of supply water treatment technologies in a particular waterworks in Chongqing.

Abstract:In order to solve desiccation cracks of conventional compacted clay cover system in arid and semiarid areas, three alternative evapotranspiration (ET) covers were proposed.One alternative option configuration consisted of 1m vegetation soil layer and 1m barrier soil layer, while two additional alternatives contained biointrusion barriers layer placed at different depths within the structural profile.Considering precipitation and evapotranspiration, a onedimensional moisture transport model through multilayer unsaturated soil was developed.By the case study of four covering systems under precipitation and evapotranspiration intensity of Dalian city at 1976, it was shown that the compacted clay layer of the traditional landfill cover could not get effective moisture charge.ET cover act as a reservoir during precipitation events and subsequently returned it to atmosphere as evapotranspiration.The biointrusion barriers layer located in the second ET cover design would restrict animal movement and play a key role in drainage.Consequently, these results would be used to assist in decisionsmaking of the landfill cover system in semiarid areas.

Abstract:To provide consultation for algae removal, an investigation on phytoplankton community in Yinluan raw water was conducted during February to October 2006.It was shown that there were 68 species of phytoplankton in Yinluan raw water, which belonged to 7 phylum and 43 genera.And the structure of the species and concentration of phytoplankton varied seasonally.Chlorophyta was dominant in spring and autumn with low phytoplankton concentration.in while summer, Microcystis flosaquae was dominant with high phytoplankton concentration, and Microcystis flosaquae's multiplying sharply lead Shannon index to decline.The correlation analysis indicated that water temperature was the key role in variation of phytoplankton community.

Abstract:A threestage seriesoperational pilot scale constructed wetland was built for domestic wastewater treatment with inflow of 4.5 m3/d .The mass balance method was adopted to quantify the transportation and transformation of pollutants in constructed wetland during steadystate operation.It was shown that the average removal rate of CODcr was 87.14%, in which 68.45% contributed by dissimilation and 18.69% contributed by assimilation.The average removal rate of TN was 60.21% and the contributions of denitrification and microbial assimilation or plant assimilation were 53.64%, 5.39% and 1.18%, respectively.The average removal rate of TP was 59.36% and the contributions of substrates absorption and microbial assimilation or plant assimilation were 43.55%, 12.26% and 3.55%,respectively.In conclusion, microorganisms played a key role in the removal of pollutants and substrates adsorption was the main approach to phosphorus removal.

Abstract:An integrated water pollution management system for the Three Gorges Reservior Area (TGRA) titled as WPMIS_ER_TGRA was developed as an informationbased techenical tool for emergency response on water pollutant accident.ArcGIS Engine, a Geographic Information System (GIS) Module Warehouse, was used as programme developing platform, and Visual Basic (VB) as programming language.The mathematical models for hydraulic and water quality simulation were developed and integrated in the system and programmed as a DLL file via VB.WPMIS_ER_TGRA owns a new function of emergency lightening at watershed scale as well as the normal water environmental information management functions.The system was applied for emergency water pollution management by a dummy ship capsizal in Yangtze River.It was found that WPMIS_ER_TGRA could model the transfer and diffusion of the accident pollutants in rivers, quickly forecast the pollution situation and identify the influencing area and their changing with time in a few minutes just after the accident happened.

Abstract:The effects of initial high humid aircuring, standard watercuring and sealedcuring on thaumasite form of sulfate attack (TSA) of cementbased materials were studied.The Erosion products after 180 days attack in sulfate solution were analyzed by the way of Xray diffraction(XRD) and fourier transform infrared spectroscopy(FTIR).And it was found that the TSA of the cement stone was delayed in high humid air resulting from that CaCO3 generated from carbonation was filled in the pores of the specimens, forming a compacted surface and restricting SO42- intrusion.In comparison, the extent of TSA of the specimens cured in sealed condition was most severe resulting from that large amount of interdefects in specimens for the lower hydration degree, and SO42- ions could intrude into specimens more easily.

Abstract:It is beneficial for disposal and utilization to improve thickening and dehydration properties of sewage sludge.The influence of dosage and fineness of shale on sludge settlement were investigated experimentally.And It was shown that the addition of shale could improve the sludge thickening without volume increment when the shale dosage with fineness of 250～150 μm was less than 5%.The moisture content of thickened and dehydration sludge with 5%shale dosage were 80% and less than 60%, respectively.The addition of shale during the sludge settlement could improve the uniformity of the mixture of sludge and shale, which was favorite for producing building materials, and alleviate the smell of sludge in despite of increase in some extent in volume afterdehydration.The dehydrationsludge modified by shale could be used as raw materials to produce excellent expanded shale.