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Xiang Y.-Q.,Zhejiang University | Xing C.,Zhejiang University | Shao L.-H.,Huahui Engineering Design Group Co. | Xing Y.,Huahui Engineering Design Group Co. | Zhao T.-Y.,Huahui Engineering Design Group Co.
Zhongguo Gonglu Xuebao/China Journal of Highway and Transport | Year: 2013

In order to simplify the calculation for lateral load distribution of hollow slab beam bridges strengthened by transverse prestress, based on the features of the strengthened bridges, the slab beams were simulated as orthotropic plates. An assumption was introduced to calculate the longitudinal and lateral stiffness of the simulated orthotropic plates. The modified G-M method was proposed to predict and analyze the lateral load distribution of the strengthened bridges. Meanwhile, two typical hollow slab bridges were taken as examples for analysis with the proposed modified G-M method and numerical finite element method. The analysis results were compared with the static load test data. The results show that the mean error is less than 6% between the lateral load distribution coefficients calculated by the modified G-M method and that by numerical finite element method and they accord well with the experimental test data; as for the side beam, the result calculated by the modified method is 3.9% larger than the experimental result, which gives a considerable safety stock. Thus, the modified G-M method is reasonable and feasible. It provides a convenient and practical way to evaluate the lateral load distribution of transversely strengthened hollow slab bridges.


Yang Q.-W.,Shaoxing Institute of Arts and science | Zhou W.-D.,Huahui Engineering Design Group Co. | Liang C.-F.,Shaoxing Institute of Arts and science
Zhendong yu Chongji/Journal of Vibration and Shock | Year: 2014

The static response-based structural damage identification methods have received much attention in civil engineering field in recent years. A static rank analysis of a structure's system matrix method was presented here for structural damage identification using its static response data and the matrix rank analysis theory. Firstly, the rank varying of a structure's system matrix due to its damage was analyzed and then a limited rank solution formula of structural flexibility perturbation was developed. With the flexibility change determined, the elemental damage parameters were calculated by using the new flexibility perturbation method. According to the elemental damage parameters, the damage position and damage level were determined. Being different from the existing detection techniques, using the presented method could directly compute the damage parameters with the incompletely measured static data. The efficiency of the proposed method was demonstrated with a numerical example. The effect of measurement of noise on damage detection performance of the proposed method was also investigated. The results showed the good efficiency and stability of the proposed method for the identification of damage of a structure with more than one element. For the case with 3% and 10% noise, the prediction obtained was also reasonable.


Zhang X.,Hunan University | Gong G.,Hunan University | Zhou J.,Huahui Engineering Design Group Co.
Key Engineering Materials | Year: 2012

Compound condensing heat pump combines the advantages of heat pump technology and condensing heat recovery technology. It takes full account of the common infrastructure in the cooling and heat source system and greatly increases equipment utilization ratio. It also recycles condensing heat to produce sanitary hot water efficiently while ensuring cooling and heating of heat pump to achieve the same effect. The distinctive technical features of the compound condensation / evaporation of four functional heat pump ensure its efficient and reliable operation. This heat pump system runs in several models throughout the year, which include the refrigeration mode, refrigeration & domestic hot water mode, domestic hot water mode and heating mode. The performance in refrigeration mode and refrigeration & domestic hot water mode is studied by a designed experiment is done and the an explicit analysis is made. By comparing the results of simlation and experiment, an agreement can be shown clearly. Therefore, the final conclusion is drawn: the performance of compound condensation / evaporation of four functional heat pump is improved over the traditional heat pump. It is worthy to further promote for the sake of energy saving. © (2012) Trans Tech Publications.


Xiang Y.-Q.,Zhejiang University | Xing C.,Zhejiang University | Shao L.-H.,Huahui Engineering Design Group Ltd. Co. | Xing Y.,Huahui Engineering Design Group Ltd. Co.
Advanced Materials Research | Year: 2012

Aiming at the features of the articulated hollow slab beam bridges with transverse prestressed force, an assumption that regards the reinforced slab beam bridges as analogy orthotropic plate was proposed. The lateral flexural stiffness and torsional stiffness of the plate bridges per meter width can be calculated approximately as an average value of those of the solid section and the minimum hollow section. The longitudinal flexural stiffness and torsional stiffness per meter width remain the same as the original ones. The modified G-M method for calculating the strengthened bridge was proposed. Example as a typical hollow slab bridges, the lateral load distribution influence-line after strengthening bridge obtained by using modified G-M method. The numerical analysis before and after strengthening bridge by using FEM was complete to gain lateral load distribution influence-line. It shows that the values predicted by the proposed modified G-M were matched with the results by the FEM after strengthening bridge. It shows that the method strengthening articulated hollow slab beam bridges by exerting transverse prestress steel wire on them proved to be effective and the presented modified G-M theory to be right. © (2012) Trans Tech Publications, Switzerland.


Zhou W.,Huahui Engineering Design Group Co. | Yang Q.,Shaoxing University | Zhao W.,Jinan University
Jixie Qiangdu/Journal of Mechanical Strength | Year: 2014

A flexibility difference method based on the minimum-rank solution for locating damage in beam structures has been proposed in this paper. This method is based on the estimation of changes in the flexibility matrix by using the static response data and the minimum rank update theory. The main advantage of using the static data rather than dynamic data is that the static equilibrium equation is solely related to the structural stiffness, and accurate static response data can be obtained rapidly and cheaply. As distinct from the existing minimum-rank methods, the presented method can directly compute the flexibility perturbation using the incomplete measured static data. Moreover, the proposed theory provides an insight to the appropriate number of the applied static loads for structural damage detection. The efficiency of the proposed method is demonstrated by two numerical examples. The results show the good efficiency and stability of the proposed method on the localization of damage. It has been shown that the proposed procedure may be a promising method in structural damage localization.


Zhou W.-D.,Huahui Engineering Design Group Co. | Yang Q.-W.,Shaoxing College | Zhao W.,Jinan University
Zhendong yu Chongji/Journal of Vibration and Shock | Year: 2013

A generalized flexibility perturbation approach for structural damage detection was presented here under ambient excitation. By appropriately converting the generalized flexibility perturbation equation, the mass normalization coefficients a structure's first several modal of shapes and the elemental damage parameters were calculated simultaneously using the least-square method. With the proposed approach, not only the damage level of the structure was recognized, but estimates of the mass normalization coefficients also were obtained. The effectiveness of the proposed method was illustrated using the simulated data and the measured noise for an example of a two-storey frame structure. The results showed that the proposed method can be used to identify structural damages accurately only using a structure's first several modal shapes; the predicted mass normalization coefficients of the measured modal shapes with the proposed method have a good accuracy; the proposed procedure is computationally attractive and simple to implement, it is useful for structural damage identification under ambient excitation.


Xiang Y.Q.,Zhejiang University | He X.Y.,Zhejiang University | Xing C.,Zhejiang University | Kordestani H.,Zhejiang University | Shao L.H.,Huahui Engineering Design Group Ltd. Co.
Bridge Maintenance, Safety, Management and Life Extension - Proceedings of the 7th International Conference of Bridge Maintenance, Safety and Management, IABMAS 2014 | Year: 2014

In this paper the major types of piers, abutment and foundation in substructure of RC or PC bridges in China are summarized. The main types of defects occurring in substructure of concrete bridges including uneven settlement of foundation, lower carrying capacity, durability defects of reinforced concrete and cracking of concrete pier columns as well as abutments and cap beams have been pointed out. In addition to the concrete pier, abutment and foundation, the causes and mechanisms of these defects were analyzed from different points of view such as design, construction, maintenance and operation management. The relevant maintenance and strengthening methods were discussed and put forward, such as the foundation enlargement method, adding pile method and artificial foundation reinforcement method for concrete and RC pier or abutment foundation, the method of RC pier columns reinforced by RC hoop or FRP for piers, the reinforcement method of pasting steel strip or plate, the method reinforced by external prestressed tendons and additional support columns method for RC cap beams, the method of reducing load, the method of reducing fill height by adding numbers of approach spans, the support beam method and the method reinforced by auxiliary retaining wall for RC abutments. It is possible to recover the function of the RC or PC bridges and enhance their durability and load carrying capacity by employing corresponding maintenance and strengthening measures. At the same time, vehicle overload should be strictly limited according to the structural safety matters. © 2014 Taylor & Francis Group.


Jiang P.,Shaoxing University | Xiao J.,Huahui Engineering Design Group Co. | Lu X.,Shaoxing University | Zeng H.,Shaoxing University | And 2 more authors.
Electronic Journal of Geotechnical Engineering | Year: 2016

Thermal conductivity is a significant parameter for studying the temperature effect of soil mechanical behaviours, and the thermal conductivity of soil particles has important influence on the calculation of soil thermal conductivity. As it is difficult to obtain the thermal conductivity of soil particles directly from test, it is usually obtained indirectly based on the inversion calculation of soil thermal conductivity. According to the characteristic of series parallel calculation prediction model of soil thermal conductivity, based on particle swarm optimization algorithm, the thermal conductivity of soil particles was inversely calculated by using the thermal conductivity of dry soil with different porosity; and the determination method of interpolation coefficient was also verified. The thermal conductivity of four kind's soil particles of peat silty clay, silty clay, gravel and gravel soil was inversely calculated to verify the accuracy of this model. The calculation results show that this prediction model can accurately determine the thermal conductivity of soil particles with a wide range of engineering applications. © 2016 ejge.


Zhou W.,Huahui Engineering Design Group Co. | Yang Q.,Shaoxing University | Zhao W.,Jinan University
Jixie Qiangdu/Journal of Mechanical Strength | Year: 2016

In this study, a method is proposed to identify structural damages by the change of structural generalized flexibility. By adding known masses to the physical structure, measuring the lower modes of the mass-modified structure, and then using these new data as well as the original test information, structural damages can be detected using the generalized flexibility perturbation technique. The effectiveness of the proposed method is illustrated using simulated data on a plane truss structure. The results show that the proposed method can identify structural damages accurately only using the first modal parameters. The presented scheme may be useful for damage identification of large-scale structures. © 2016, Journal of Mechanical Strength. All right reserved.

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