Wang L.-L.,Shanghai Municipal Engineering Design General Institute Group Ltd Corporation |
Wang L.-L.,Tongji University |
Chen W.,Hohai University |
Lin T.,Hohai University
Zhongguo Kuangye Daxue Xuebao/Journal of China University of Mining and Technology | Year: 2011
In order to reduce the biological risk caused by bacteria attached to carbon fines (BACF), the characteristics of carbon fine and the bio-chemical mechanism of bacteria were analyzed. Furthermore, the desorption principle of BACF were discussed. Through the orthogonal test and comparative study, a new collaborative method of high-speed centrifugation and desorption agent was developed to weaken various forces between bacteria and fines and to improve the desorption efficiency. Then the suitable conditions about high-speed centrifugation and combination of desorption agent were further optimized. The results demonstrated that desorption efficiency could be improved by 75.6%. The best desorption ratio of BACF was to 15.1 times under the optimum centrifugal conditions, which were high-speed centrifugation (18×103 r/min, 5 min, 4°C and the solution combination (sodium pyrophosphate 0.01%; tris buffer 0.01 mol/L, pH7.0; peptone 0.01%; surface active agent 1 μmol/L; EGTA 1 mmol/L). The bacteria were generally separated from the fines during the experiment. The results were significant in controlling the biological safety in GAC process effluents.
Wang L.-L.,Shanghai Municipal Engineering Design General Institute Group Co. |
Wang L.-L.,Tongji University
Proceedings - 2013 4th International Conference on Digital Manufacturing and Automation, ICDMA 2013 | Year: 2013
A computational fluid dynamics (CFD) model is used to assess the effect of pump layout program on flow field in Ditch-V pump station for potable water treatment. The model is based on the CFD code Fluent and exploits several specific aspects of the potable water application to derive a computational tool much more efficient than the corresponding tools employed to simulate booster pump station projects. To research the flow field of deflector program in super pumping station with many restriction factors such as large flow quantity, high pumping lift and three different water supply directions, an incompressible turbulent fluid velocity field model and multi-hydraulic model was established. Then flow field was calculated and analyzed using control volume method. Therefore, the objective of this study was to determine the size of the deflector program in the water supply. The present model is adjusted against data from a real pump station and then it is used to assess the significance of influent structure and diversion variation. It is found that the flow pattern in transition section of symmetric trapezoidal layout program was smooth, and had little water loss. Flow pattern near the bottom in the fore-bay was smoother, while vortex and roll back flow was formed near the front surface of the pool. Some program improvements were made during numerical simulation including increasing the length of canals, changing configuration forms and adding diversion cone. Numerical simulation results indicated that the inlet drift angle below the pump was generally less than 4°. Flow field near the suction pipe was smooth and uniform. © 2013 IEEE.
Hu A.-F.,Zhejiang University |
Rao H.,Zhejiang University |
Rao H.,Shanghai Municipal Engineering Design General Institute Group Co. |
Yuan J.,Zhejiang Province Institute of Architectural Design and Research
Yantu Gongcheng Xuebao/Chinese Journal of Geotechnical Engineering | Year: 2012
As a technique for protection of adjacent buildings, the outrigger-type diaphragm wall been applied in deep excavation engineering. But the worldwide researches in this area are still relatively scarce until now. In extension project of Hangzhou Huanglong Hotel, outrigger-type diaphragm walls are adopted to solve the problem of insufficient rock-socketed depth. And thus the rock-socketed depth of support structures in intermediary weathered rock is ensured. Moreover, the construction difficulty is reduced. Good social and economic benefits are gained. Based on the Huanglong excavation case, a 3-D finite element model is presented to simulate the behavior of outrigger-type diaphragm walls by using the software ABAQUS. The behavior of soil is assumed to conform to the modified Cam-clay model, and the actual construction sequence is simulated. The numerical results and monitoring data in the excavation of lateral displacement are compared. The reasonable stiffness of the section steel in the outrigger-type diaphragm walls is also analyzed.
Liu F.Q.,Shanghai Municipal Engineering Design General Institute Group Co.
International Journal of Geomechanics | Year: 2014
The slip line method has been extended to consider the tangential stress and arbitrary magnitude of wall movement. An analytical solution has also been proposed for the arbitrary mode of wall movement, and the soil mass behind the wall can be homogeneous or layered. The mobilized internal friction angle of the soil and the soil-wall interface friction angle change with the movement of the wall; this has been widely accepted. However, the development of them is not simultaneous. The mobilized friction angles are used in the slip line method and the simplified slip line method to yield the nonlimit lateral earth pressure. Results indicate that earth pressure decreases exponentially with increasing wall movement. Comparisons of the calculated results with measured data and FEM results show that the present analytical method can provide good prediction of the lateral earth pressures and the limit wall movement equal to 0.3%H is appropriate in the calculation (where H is the excavation depth). © 2014 American Society of Civil Engineers.
Li X.,Shanghai Municipal Engineering Design General Institute Group Co. |
Shi X.,Tongji University |
Ruan X.,Tongji University
Wuhan Ligong Daxue Xuebao (Jiaotong Kexue Yu Gongcheng Ban)/Journal of Wuhan University of Technology (Transportation Science and Engineering) | Year: 2012
To control cracks and large deflection in long-span concrete bridges, sufficient large-tonnage pre-stressing forces are usually applied in curved bottom slabs. In this case, curved bottom slabs in box girders are under state of high stress and duct opening ratio. Consequently, more serious accidents like concrete near pre-stressing ducts completely damaged and bursts into two parts during the process of closure in main span happen frequently in recent years. In the paper, the whole process of typical burst failure of curved bottom slab in a pre-stressed concrete bridge is reappeared by using facilitated numerical computation analysis in consideration of nonlinear characteristic of materials. The mechanism of crack arises, damage course and actions of different types of reinforcements in bottom slab is quantitatively studied during the construction process.
He C.-X.,Shanghai Municipal Engineering Design General Institute Group Co.
Wuhan Ligong Daxue Xuebao/Journal of Wuhan University of Technology | Year: 2011
This study investigates the effects of different aggregate gradations and compaction number on road performance of asphalt mixtures. The dynamic stability, low temperature bending failures strain, soaking marshall stability, AASHTO T283, split strengthen and freeze-thaw split strengthen are used to evaluate the road performance. Three gradations (Sup13, Sup20 coarse and Sup20 fine) and two compaction (100, 125) number were selected. Means comparison using Tukey test is used to analyze. Increasing compaction number would bring on higher dynamic stability, low temperature bending failures strain, split strengthen and freeze-thaw split strengthen. Compared with fine gradation, coarse gradation gives higher dynamic stability, low temperature bending failures strain, split strengthens and freeze-thaw split strengthen under the same compaction number. There are no significant differences between water stability with coarse and fine gradation or different compaction number. Coarse gradation is top-priority compared with increasing compaction number.
Zhao C.,Tongji University |
Du X.-H.,Tongji University |
Du X.-H.,Shanghai Municipal Engineering Design General Institute Group Co. |
Zhao C.-F.,Tongji University |
And 2 more authors.
Yantu Gongcheng Xuebao/Chinese Journal of Geotechnical Engineering | Year: 2013
To solve the disadvantages of the traditional construction methods for prestressed pipe piles like squeezing effect and noise and to expend their application, a new construction method, inner-digging method is studied. The static load test and other series field tests on hammer piles and inner-digging piles and are discussed, the vertical compressive properties and rules of load transfer of different kinds of piles are investigated. The test results show that the rules of load transfer of inner-digging pipe piles is the same as those of other kinds of piles. The inner-digging method will reduce the pile side resistance and make it lower than that of hammer-piles, but the post-grouting technology can effectively develop the ultimate bearing capacity. The ultimate bearing capacity of inner-digging piles is close to that of hammer piles, which can meet the requirements of construction and will have a good population and application value in the future.
Wang L.,Tongji University |
Wang L.,Shanghai Municipal Engineering Design General Institute Group Ltd. Co. |
Chen W.,Hohai University |
Lin T.,Hohai University
Chongqing Daxue Xuebao/Journal of Chongqing University | Year: 2012
UE extraction and GC-MS determination are used to analyze organic ingredients adhesion to particles in GAC effluents, and examine the types, characteristics, sources, transformation mechanisms and distribution of organic matter attached to particles. The results indicate that the weak polar organic adhesion to particles in GAC effluents mainly included the hydrocarbons(37.75%), esters and ketone(32.60%). There is a slightly different amount of organic matter attached to particles with different sizes. The transfer and transformation of organic matter attached to particles present the changes of number and type of functional group, and molecular structure determined the migration and transformation behavior of physical and chemical properties of organisms in the environment, and the internal eco-toxicological effects. And on this basis, it is necessary to control the number of effluent particles to reduce THMs and improve chemical security.
Liu K.,Shanghai Municipal Engineering Design General Institute Group Co. |
Zhao C.-F.,Tongji University
Yantu Gongcheng Xuebao/Chinese Journal of Geotechnical Engineering | Year: 2011
The primary goal of this research is to study the influences of different pile-tip soils on the bearing characters of bored piles. Soils laid around and under piles are selected based on characteristics of strata passed through by bore piles in soft soil. Prefabricated model piles are pre-installed onto the pile-tip soils with film around them to remove influences induced by differences in coarse degree and diameter of piles, and to produce unloading effect on piles. Test data are gained after static loading tests on six model piles, and the influences on side resistance are discussed. Relations between side resistance and relative displacement are established and normalized to quantitatively solve the problem. It is concluded that the model tests on the influences of different pile-tip soils on the bearing characters of bored piles are valid, and more test data and project practice are needed to solve this problem thoroughly.