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In design of aqueduct structure, natural frequency calculation is the basis of earthquake response analysis. In this paper, the dynamic characteristic of Gegou U shape aqueduct is calculated by the finite element software ANSYS. And in this software, the interaction between water and aqueduct wall is simulated with added mass method. Natural vibration frequencies and principal modes of Gegou U shape aqueduct are analyzed and calculated in four different water level which include empty tank water level, semi tank water level, design water level and bank-full water level. The calculation results show that the water level has a great influence on the natural frequencies of the aqueduct and the frequencies decrease with the increase of water level. The research results can provide basis for its protection and seismic design of U shape aqueduct. Keywords-Gegou aqueduct; ANSYS; natural frequency; vibration mode; added mass

In this paper, the finite element method was used to analysis the modal characters of a reinforced concrete pedestrian bridge structures. The relationship between parameters and structural vibration frequency was found by parametric analysis. Structural dynamic conditions corresponding state occurred was mainly determined by main modes. In practice, simulated operation, bridges can be analyzed by the previous stage of the natural frequencies and the mode shapes in order to assess. Keywords-pedestrian bridge; modal analysis; dynamic characteristics; natural frequencies; mode shapes

As part of a study to assess the efficacy of impregnation for masonry substrates, the impregnation of mud bricks with soluble sodium silicate followed by water-based organic silicone emulsion was investigated. The treatment was found to be successful in achieving water repellent and consolidation effects for the mud bricks. The durability of the treated mud bricks was examined through water absorption, depth of impregnation, resistance to water penetration, wetting and drying cycling, and UV/condensation weathering tests. The mechanism of water repellent and consolidation effects for the mud bricks is discussed.

As part of a study to assess the efficacy of impregnations for masonry substrates, the treatment of concrete with soluble silicate solutions and further treatment with various curing agents have been compared. Tests were performed on small specimens in the laboratory. Impregnation of permeable concrete with soluble silicate solution followed by impregnation with a dilute solution of particular alkyl quaternary ammonium salts reduced the rate of water absorption significantly. The water vapour permeability of the substrate was not significantly affected.