Electrochemical Study of Stainless Steel Anchor Bolt Corrosion Initiation in Corrosive Underground Water

Application of low-nickel stainless steel anchor was one of the economical and effective methods to solve the durability problem of slope engineering. At present, there are scarce reports about corrosion characteristics of low-nickel stainless steel in various underground waters. For investigating the corrosion initiation of stainless steel anchor bolt in corrosive underground water, the effect of SO42−, HCO3− and pH value on the corrosion behavior of 201 low-nickel stainless steel was studied via electrochemical methods. As the SO42− concentration, HCO3− concentration or pH value increase, the open circuit potential and polarization resistance increase, while the double-layer capacitance, donor density and passive current density decrease. The results indicate that corrosion is inhibited by SO42−, HCO3− and OH− in underground water. In addition, the inhibitive efficiency of SO42− and HCO3− increases with the SO42− and HCO3− concentration.

Evaluation Method of Complex Slope Stability in Construction Industry Based on Correlation Calculation

Based on the basic-element expression method and correlation function theory in Extenics, combined with the knowledge of slope engineering, a method for evaluating the stability of complex slope is proposed. The evaluation process includes the selection of suitable evaluation indexes of slope stability, identificationof the classification standard for the slope stability, identificationof the weights of evaluation indexes by using the improved analytic hierarchy process,identificationof the classical domain, node domain and matter-element under evaluation,the calculation of the correlation of each stability class for each evaluation index, normalization of correlation,and so on. The selection rule of the slop stability evaluation indexes and selection of correlation function and optimal points are also discussed, which can provide reference for slope engineering designin construction industry.

Moisture Characteristics of Improved Gravelly Guest Soil for Bio-slope-engineering

This paper explores the reasonable proportion of guest soil in bio-slope-engineering by means of proportional experiments. In the experiment, rubble and improved materials such as peat and water-retaining agent were selected to study the effect of peat and water-retaining agent content on moisture constant, permeability coefficient and water absorption rate of guest soil.The measurements showed that peat and absorbent agent improve effective water capacity and water absorption speed of guest soil, thus guest soil absorb and hold more effective water; however, with the increase of peat content, wilting moisture capacity of guest soil will increase and its permeability coefficient will also enlarge, which is a disadvantage to plants survival in drought conditions and slope stability in rainy seasons. According to guest soil’s proportional experiments and field test, the favorable amount of rubble, peat, absorbent agent and aggregate agent, is 80%, 20%, 1.0‰ and 1.0‰, respectively, and the reasonable content of fertilizer in guest soil is 100 g/m2. The results may guide the design and construction of Guest soil spraying for bio- slope-engineering.