Advanced Materials Research Vol. 859

Abstract: The main focus is to present an urgent reinforcement for a power transmission tower foundation beside a slope. The method is based on the theory of the uplift and down-pressure lines in low slope. The strategy adopts the geosynthetic-reinforced gunite concrete and two-storey retaining wall to reinforce the slope. The results show that the theory of the uplift and down-pressure lines in low slope can be used in the slope with the height of 10m by combining retaining wall reinforcement. The heavy excavation under the transmission tower foundation is avoided by using the inclined back along the edge of the balance-weight retaining wall. The compound clay backfill provides sufficient strength for two-storey retaining walls beside the slope.

Abstract: The soil layers around the tunnel were equal to cohesionless homogenate mass by introducing the concept of equivalent internal frictionangle in this paper. Based on the Terzarghi unconsolidated mass theory, the soil arching effect of existing open trench tunnels under ground asymmetric load is discussed. Furthermore, the critical embedded depth formula of soil arching effect is given. Finally, it is concluded that both the size and distribution of the ground asymmetric load have influence on soil arching effect of existing open trench tunnel.

Abstract: Based on Terzaghi's theory on loosening earth pressure, two failure modes of soil upon shallow EPB shield tunnel caused by synchronous grouting are analyzed, and the theoretical equations of synchronous grouting pressure is built to calculate the maximum and minimum grouting pressure which correspond to the limit states of subsidence and upheaval failure. Combined with a shield tunnel construction practice, the theoretical and measured values are compared. The results show that the theoretical equations are valid and can provide a theoretical approach for the parameters of shield synchronous grouting.

Abstract: To study the internal force redistribution of high strength outer-plated steel-high strength concrete continuous composite beam, static load tests of two continuous composite beam specimens were conducted. The paper analyses the causes of internal force distribution of continuous composite beams. By using high strength steel and high strength concrete reasonably, plastic strain on sections of both the negative and positive maximum moment got fully developed at the load-bearing limiting state, and the continuous composite beams have sufficient plastic rotation ability and ductility to develop full moment redistribution.

Abstract: The shear stress transfer of prestressed anchor is the key for anchor performance and engineering design. The interface bonding strength between soil and induration has a very important role in supporting capacity of the soil anchor. It is presumed that the deformation between the soil layer rod and induration is compatible after the sliding section. Based on the Mindlin solution of a force act on the interior of a semi-infinite solid, a theory solution for the shear load of anchorage section is solved by considering the part of slip characteristics of interface in the loading process. On this basis, the shear stress of anchorage section is tested from anchor pullout test on site. Contrasted with the tests result, it is proved that the theoretical analysis is consistent with the tests. Theoretically, the research of shear stress transfer will enrich and develop anchor cable theory.

Abstract: The correlation of failure modes needs to be considered in the reliability analysis of foundation excavations system. Because it is difficult to calculate the correlation coefficient of failure modes, the computational efficiency of traditional method is low. In this paper, the response surface (RS) is established by using the uniform test and support vector machine (SVM). On this basis, in order to obtain the index of each failure mode, the random parameters generated by Monte Carlo simulation are predicted. Combined with the Pearson correlation analysis, the correlation coefficient of failure modes is obtained. And then, the Breadth Border Method, Narrow Bounds Method and PNET method are used to calculate system failure probability of foundation excavations. The reliability analysis method of the foundation excavations system based on the response surface of the support vector machine (RSSVM) is put forward. The instance analysis shows that the method is simple in calculation, and provides a convenient way for the system reliability theory of foundation excavations.

Abstract: Fulvic acid solution whose the pH value is at 2.9 and 3.5 is adopted to conduct immersion test of three days cured red clay-cemented soil composite mass. Through monitoring the acid consumption and specimen appearance, the corrosivity and mechanism of red clay-cemented soil composite mass while under the fulvic acid circumstances is studied. It is showed that fulvic acid has some corrosivity to the composite mass. The smaller pH value is, and the more severe corrosivity is. The erosion process can be divided into quick response and stable stages, where the former stage is the primary and the latter is weak.

Abstract: Three isomers, [4'-(bisphenylamino)[1,1']biphen-2-yl]methylenefluorene (BAB2MF), [4'-(bisphenylamino)[1,1']biphen-3-yl]methylenefluorene (BAB3MF) and [4'-(bisphenylamino)[1,1']biphen-4-yl]methylenefluorene (BAB4MF), were synthesized through Suzuki coupling. The substitution pattern exerts a dramatic influence on the optical property. BAB3MF and BAB4MF are hardly emissive either in the solution or as solid state. On the contrary, BAB2MF emits strongly, especially in the aggregate state with a high fluorescent quantum yield of 69%. Furthermore, BAB2MF shows an aggregation-induced enhanced emission behavior. BAB2MF solid emits at 488 nm, about 60 nm blue-shifted from its solution.

Abstract: La-B-TiO₂ photocatalysts were prepared using tetrabutyl titanate, tributyl borate, and lanthanum chloride as the precursors by solvothermal method. The prepared sample is composed of irregular particles with fairly rough surface in the size within 5 μm. Large surface area and pore volume are benefit to adsorption and photocatalytic degradation activity of the materials. Pore size of the 1%La-3%B-TiO₂ sample mainly distributes in the range between 5-35 nm. Specific surface area of the material is 101.45 m²/g. The sample containing 0.5% La presents the maximum decoloration efficiency. When La content is 0.5%, methyl orange adsorption rate on the material is less than 5%, and photocatalytic degradation rate is 39.9%.

Abstract: Treatment of protected furanoses with FeCl₃·6H₂O in acetonitrile with microwave irradiation provides an efficient and mild protocol for regioselective removal of anomeric O-acetyl group. This method features cost efficient reagents, simple procedures, and high yields. The experimental results proved that microwave irradiation could notably shorten the reaction time and increase the product yield compared to the conventional thermal heating condition.