Applied Mechanics and Materials Vols. 438-439

Abstract: In order to ensure the safety of the curved girder bridge operations, the actual testing is necessary to determine the impact of various factors on the horizontal offset of the bridge bearing against bearing defects. In this paper, finite element analysis with Midas/Civil is applied to each factor separately to get the spherical bearing offset of various factors which compared with the actual displacement analysis, and get the impact the bridge itself gravity, the vehicle load generated by the centrifugal force and the temperature load to the spherical bearing horizontal offset. The analysis results show that the main reason of the spherical bearings horizontal offset is climb shift of the bridge in temperature load. On this account, make effective measures for the protection and repair of bridge to ensure the safety of the bridge operations.

Abstract: In order to overcome the defects of the classical model in the description of the rheological properties of soft soil, an Abel glue pot was defined based on the fractional derivative theory by the fractional calculus of Riemann-Liouville. Three components fractional order derivative solid model was built with Abel glue pot. Then the experimental data was fit using the new model. The simulation results show that the three components fractional order derivative solid model is more accurately than the generalized Kelvin model or Burgers model and that it has few parameters.

Abstract: The paper based on the site of a subgrade compaction test data, used the continuous compaction indicator CMV as the analysis variable, filtered the date based on the influencing factors of CMV, and used the common probability models for statistical analysis,finally got the probability distribution models with which the CMV data comply, then chose the most accurate distribution model. The result showed that the lognormal distribution was the most accurate distribution. After being examined in two other test sections, the lognormal distribution was also the most accurate distribution. It provides a reference for the continuous compaction quality testing of the subgrade.

Abstract: The Longjiang Bridge is a kilometer level suspension bridge supported by reinforced concrete towers. The towers will be founded on pile group foundation, and the project area is in a mountain region of high earthquake probability. Two seismic schemes were designed for the bridge, and two computational bridge models in full size were established, extensive studies were performed to capture the seismic response of different schemes for the earthquakes. The results show that towers composed of two curved quadrilateral hollow concrete columns are adopted for the bridge.

Abstract: Elastic modulus of soil increases continuously with depth because of the overburden pressure. By combining the modified Mohr-Coulomb elastic-plastic constitutive model with this type of nonhomogeneous subgrade and considering factors of embedment depth of foundation, friction coefficients between the foundation bottom face and soil, the nonhomogeneity and strength of subgrade soil are analyzed by FEM method. It is shown that the settlement laws of the magnitude and the distribution range of the subgrade are different to other models using in literatures ordinarily

Abstract: The urban underground pipe network plays a vital role in the city development, the construction of unreasonable urban pipe networks restricts the city development, even has a disastrous effect on the city. However, it is not desirable to overstate the investment of the urban underground pipe network excessively. It is an important subject of the city construction that how to establish reasonable urban pipe networks to meet service conditions of underground pipe networks. Because the construction of underground drainage pipe networks of most of the major cities in our country mainly comes from the 50s of last century and there are more pipe network system with the development of the city, it is the main content of our research that how to reform and construct them under the condition of existing underground pipe networks.

Abstract: The paper mainly introduces the problem of grouting reinforcement of buildings over the old goaf, and presents to the positioning of grouting reinforcement technology in the goaf. Combined with engineering example, the paper discusses the grouting filling method to strengthening governance goaf. Three methods including drill detection, ground penetrating radar (GPR) detection and electromagnetic wave CT method are used for integrated detection.

Abstract: Based on the platform of LabVIEW, a set of roller intelligent detecting system is developed. With this system, it is easy to realize functions of fast nondestructive testing of subgrade compaction degree, roller speed, rollers compaction trajectory, compaction times, GPS real-time positioning as well as saving and printing report forms. Compared with traditional detection methods, this detecting system can test and control on-site compaction quality much more easily, in order to speed up the construction progress, improve the quality of subgrade compaction, control and manage compaction work better.

Abstract: Coarse-grained soil is widely used in railway construction, and it is of great significance to take research on how compression deformation characteristics affect deformation of coarse-grained soil in high filled subgrade. To analyze compression deformation characteristics of coarse-grained soil under different moisture content and different grain compositions conditions, influence pattern of moisture content and grain compositions was researched through uniaxial compression test. The result indicates that compressive deformation is in logarithm relation with time; moisture content and grain compositions are important factors that affect the characteristics of compressive deformation of sandy slate coarse-grained soil and it is better to control subgrade settlement with dry or saturated coarse-grained soil which contains 70% coarse particles.

Abstract: Prestressed concrete continuous wide box girder bridge is widely used in urban bridges, because of its large width-span ratio, spatial effects from unbalance load cannot be ignored. When the bridge was analyzed by beam element system, the increased coefficient of unbalance loading is used to simplified space problem into plane problem. Spatial effect of wide box girder under unbalance loading is calculated by solid finite element method, and used in a project example in Hangzhou. Comparing analysis results of solid finite element with other simplified methods, it shows that the solid element method is more applicable and accurate. This method and results offer reference for similar bridge design calculation.