Guangzhou Municipal Engineering Design and Research Institute
Guangzhou Municipal Engineering Design and Research Institute
Pan H.,South China University of Technology |
Su W.,South China University of Technology |
Su W.,Guangzhou Municipal Engineering Design and Research Institute |
Zhai G.,Guangzhou Metro Company |
And 2 more authors.
Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering | Year: 2017
To avoid the disturbing to the existing underground structures, shield advancing along a path with a small radius of curvature is sometimes inevitable. In this paper, the site observation data, the vertical and horizontal deformation and the pore water pressure of soils around the tunnel, were presented and analyzed when a shield advancing through a path with the radius of curvature being 118 m. It was found that the soil deformation mode was very different from those observed in the case of straight path. The soil around the tunnel on the outside of the curve was squeezed and moved upward and the horizontal displacement of soil around the tunnel consists of two parts. One part was induced by the squeezing effect, which was similar to that induced by shield advancing through a straight path, and the other part was from the turning action. The second part is nonsymmetrical. The soil on the outside of the curve moved away from the tunnel and the soil on the inside moved towards the center of the tunnel. The superimposition of the deformation increased the risk and should be paid more attention. © 2017, Science Press. All right reserved.
Li Y.,Southwest Jiaotong University |
Cai X.,Southwest Jiaotong University |
Cai X.,Guangzhou Municipal Engineering Design and Research Institute |
An W.,Southwest Jiaotong University |
And 2 more authors.
Zhongguo Tiedao Kexue/China Railway Science | Year: 2011
The determination of structural stiffness parameters is very important in the overall design of long-span bridges. Taking a long-span railway dedicated suspension bridge as an engineering example, the effect of the stiffness of girder, tower and cable on the performances of bridge was analyzed from the aspects of the structural dynamic characteristics, train running performance and wind induced buffeting response. The stiffness assessment index for long-span railway suspension bridge was studied. Results indicate that the increase of the truss width can notably raise the transverse bending fundamental frequency of the bridge. The transverse periodic vibration of bridge would occur on condition that the truss width is too small, and the proposed limit value of the width-span ratio is 1/20~1/35. The vertical acceleration of train can be remarkably increased with the decrease of truss depth, and the proposed limit value of the depth-span ratio is 1/70~1/100. The increase of main cable stiffness can obviously improve the torsional and vertical fundamental frequency of the bridge. In addition, the effect of tower stiffness and dead load is limited.
Li J.,Guangzhou Municipal Engineering Design and Research Institute |
Sui J.,Guangzhou Municipal Engineering Design and Research Institute |
Feng Y.,Guangzhou Municipal Engineering Design and Research Institute
Chinese Journal of Environmental Engineering | Year: 2015
The principal effect of Shangxiguan creek detention tank is to intercept and store the initial stormwater from the service area so as to reduce the discharge volume and pollution loading during heavy rainfall. The calculation methods of the detention tank volume are introduced in detail. By analyzing the scouring efficiency of the initial stormwater period, the environmental effects of detention tank were assessed. ©, 2015, Science Press. All right reserved.
Wang C.,CAS Chongqing Institute of Green and Intelligent Technology |
Liu H.,CAS Chongqing Institute of Green and Intelligent Technology |
Sun Z.,Guangzhou Municipal Engineering Design and Research Institute
International Journal of Photoenergy | Year: 2012
Great efforts have been exerted in overcoming the drawbacks of the Fenton reaction for water treatment applications. The drawbacks include pH confinement, handling of iron sludge, slow regeneration of Fe(II), and so forth. This paper highlights the recent developments in the heterogeneous photo-Fenton reaction which utilizes nanosized iron oxides as catalyst for maximizing the activity due to the enhanced physical or chemical properties brought about by the unique structures. This paper also summarizes the fundamentals of the Fenton reaction, which determine the inherent drawbacks and associated advances, to address the advantages of iron oxides and nanosized iron oxides. Tips for applying this method in water treatment are also provided. Given that the environmental effect of nanosized iron oxides is not yet well established, rapid research growth may occur in the near future to advance this promising technology toward water treatment once it is smartly coupled with conventional technologies. © 2012 Chuan Wang et al.
Dai G.-L.,Central South University |
Zheng P.-F.,Central South University |
Yan B.,Central South University |
Xiao X.-N.,Guangzhou Municipal Engineering Design and Research Institute
Zhejiang Daxue Xuebao (Gongxue Ban)/Journal of Zhejiang University (Engineering Science) | Year: 2013
The calculation method of solar radiation temperature field on concrete box girder based on the ANSYS was discussed, and the calculation results were verified with the measured data. In order to calculate the temperature effect under the solar radiation, the space beam element with section information was used to simulate the continuous box beam bridge, and the nonlinear spring was used to simulate the longitudinal resistance of continuously welded rail (CWR). Taking the 6×32 m box section and prestressed concrete continuous beam as a case, the distribution law of rail longitudinal force was analyzed under the solar radiation. The impact of relevant design parameters was considered. The analysis results show that the maximum value of rail stress is got at high noon under the solar radiation and the minimum value by midnight. In accordance with the existing norms, the rail expansion force at the time of the whole beam increasing-temperature 20°C is 1.3 times as much as the rail force under the solar radiation. Increasing the slab thickness is conducive to the rail force. The rail stress is proportional to the atmospheric transparency coefficient under the solar radiation, and using light-colored coating and maintaining smoothness for the bridge deck will help to reduce the rail force.
Wen Q.,Hunan University |
Hua X.G.,Hunan University |
Chen Z.Q.,Hunan University |
Yang Y.,Hunan University |
Niu H.W.,Guangzhou Municipal Engineering Design and Research Institute
Journal of Bridge Engineering | Year: 2016
This article describes the research work relating to the assessment and control of human-induced vibration of an unusual curved cable-stayed bridge with separate road and pedestrian decks. Dynamic simulations of human-induced vibration were performed with a mode-by-mode approach, and the results showed that a total of eight lateral and vertical modes of the bridge may suffer from excessive vibrations at the design crowd density. A hybrid control scheme was developed for control of human-induced vibration, which consists of steel braces fitted between the road bridge deck and the pedestrian deck to improve structural stiffness and eddy current tuned mass dampers to enhance damping ratios of lively modes. The modal properties of the bridge with steel braces were experimentally obtained by dynamic tests and used for parameter tuning of mass dampers. The performance of the hybrid control strategy was evaluated by group tests of up to 400 pedestrians. It is shown that the critical number of pedestrians triggering synchronous lateral excitation is generally in good agreement with the empirical model developed from measurements on the London Millennium Bridge, but the measured vertical acceleration amplitude is only about 40% of the prediction under the same pedestrian density. The damping ratios for both the vertical and lateral modes increase appreciably after installation of tuned mass dampers and no evidence of large-amplitude vibrations has been observed. © 2016 American Society of Civil Engineers.
Sui J.,Guangzhou Water Investment Group Co. |
Luo F.,Harbin Institute of Technology |
Li J.,Guangzhou Municipal Engineering Design and Research Institute
Environmental Technology (United Kingdom) | Year: 2016
Short-cut nitrification (SCN) is shown to be an attractive technology due to its savings in aeration and external carbon source addition cost. However, the shortage of excluding nitrite nitrogen as a model state in an Activated Sludge Model limits the model predictive control of biological nitrogen removal via SCN. In this paper, a two-step kinetic model was developed based on the introduction of pH and temperature as process controller, and it was implemented in an SBR reactor. The simulation results for optimizing operating conditions showed that with increasing of dissolved oxygen (DO) the rate of ammonia oxidation and nitrite accumulation firstly increased in order to achieve a SCN process. By further increasing DO, the SCN process can be transformed into a complete nitrification process. In addition, within a certain range, increasing sludge retention time and aeration time are beneficial to the accumulation of nitrite. The implementation results in the SBR reactor showed that the data predicted by the kinetic model are in agreement with the data obtained, which indicate that the two-step kinetic model is appropriate to simulate the ammonia removal and nitrite production kinetics. © 2016 Taylor & Francis
Zhang W.,Beihang University |
Zou Z.,Beihang University |
Sui J.,Guangzhou Municipal Engineering Design and Research Institute
Journal of Environmental Sciences | Year: 2010
Most research conducted on the concentration distribution of sediment in the sedimentation tank does not consider the role of the suction dredge. To analyze concentration distribution more accurately, a suspended sediment transportation model was constructed and the velocity field in the sedimentation tank was determined based on the influence of the suction dredge. An application model was then used to analyze the concentration distribution in the sedimentation tank when the suction dredge was fixed, with results showing that distribution was in accordance with theoretical analysis. The simulated value of the outlet concentration was similar to the experimental value, and the trends of the isoconcentration distribution curves, as well as the vertical distribution curves of the five monitoring sections acquired through simulations, were almost the same as curves acquired through experimentation. The differences between the simulated values and the experimental values were significant. © 2010 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences.
Wang G.,South China University of Technology |
Wang G.,Guangzhou municipal engineering design and research institute |
Sui J.,Guangzhou municipal engineering design and research institute |
Shen H.,South China University of Technology |
And 6 more authors.
Journal of Hazardous Materials | Year: 2011
In this study, chlorine dioxide (ClO2) instead of chlorine (Cl2) was proposed to minimize the formation of chlorine-based by-products and was incorporated into a sequencing batch reactor (SBR) for excess sludge reduction. The results showed that the sludge disintegrability of ClO2 was excellent. The waste activated sludge at an initial concentration of 15g MLSS/L was rapidly reduced by 36% using ClO2 doses of 10mg ClO2/g dry sludge which was much lower than that obtained using Cl2 based on similar sludge reduction efficiency. Maximum sludge disintegration was achieved at 10mg ClO2/g dry sludge for 40min. ClO2 oxidation can be successfully incorporated into a SBR for excess sludge reduction without significantly harming the bioreactor performance. The incorporation of ClO2 oxidation resulted in a 58% reduction in excess sludge production, and the quality of the effluent was not significantly affected. © 2011 Elsevier B.V.
Gao S.,Harbin Institute of Technology |
Zhao Z.,PLA Logistical Engineering University |
Xu Y.,Harbin Institute of Technology |
Tian J.,Harbin Institute of Technology |
And 3 more authors.
Journal of Hazardous Materials | Year: 2014
Sulfamethoxazole (SMX), a typical sulfonamide antibiotic, has been widely detected in secondary wastewater effluents and surface waters. In this work we investigated the oxidative degradation of SMX by commonly used oxidants of chlorine, ozone and permanganate. Chlorine and ozone were shown to be more effective for the removal of SMX (0.05-5.0. mg/L), as compared with permanganate. Higher pH enhanced the oxidation of SMX by ozone and permanganate, but decreased the removal by chlorine. Moreover, the ozonation of SMX was significantly influenced by the presence of humic acid (HA), which exhibited negligible influence on the oxidation by chlorine and permanganate. Fairly lower mineralization of SMX occurred during the oxidation reactions, with the highest dissolved organic carbon (DOC) removal of 13% (for ozone). By using LC-MS/MS, 7, 5 and 5 oxidation products were identified for chlorine, ozone and permanganate and possible transformation pathways were proposed. It was shown that different oxidants shared some common pathways, such as the cleavage of S. N bond, the hydroxylation of the benzene ring, etc. On the other hand, each of the oxidants also exhibited exclusive degradation mechanisms, leading to the formation of different transformation products (TPs). This work may provide useful information for the selection of oxidants in water treatment processes. © 2014 Elsevier B.V.