Study Of Failure Mechanism And Control Measures On Anchors' Common Diseases In Clay

This paper take the anchors in soil of geological engineering as the object of study, by means of the real engineering survey, model tests and theoretical analysis, analyzed the common types of diseases and the causes of anchors in soil, besides, this paper presented with the corresponding control measures, on this basis, the proposed failure mechanism of anchors in soil:"point damage, complex control." Laid a theoretical foundation for forecast of the destruction of anchors in soil.1. Through the investigation on deep excavation, highway slope, hydropower dam where applications anchors in soil, the form of their common diseases are summarized and a preliminary analysis.2. Through tension type and pressure type anchor laboratory model test in the context of different space,the contrast analysis was carried out in a single bolt strain distribution curve, slope point out bolt, sliding surface point and end point of the anchoring section seepage around, loads of different magnitude, the strain distribution curves at different times. Given two types of bolt strain distribution curve, proposed "time effect" of the strain distribution of anchors in soil, stated the most vulnerable site to damage in the earth anchor systems, the destruction of law under the common action of the water and the applied load, and two types of distribution of internal force bolt system have been compared.3. By Marc finite element analysis,the relevant conclusions of model tests was validated, and combined with the model test and complex model, define the stress concentration factor of the anchors in soil, made in calculating the length of the effective anchorage, according to different location of anchors in soil, different safety factors were used.4. Through pullout test of the anchors in soil, the ultimate pullout force of anchor of curves with change of the water content were analyzed; and study to loss of prestressing of anchors in soil before and after the flooding,and obtained the main factors of the loss of prestress in bolt of the loess layers5. Use of Failure Mode and Effects Analysis (FMEA) to assess the safety situation of the anchors in soil, obtained the most vulnerable to damage the site of anchors in soil, and identified factors associated with the responsible departments.6. Combined with the analytical result of engineering research, test analysis, finite element simulation and FMEA analysis, and the form of common diseases of adhesive-soil soil layer anchorage and prestressed soil layer anchorage are summarized, and the damage causes were explained and puts forward some effective measures for prevention and cure.7. Based on the experimental and theoretical analysis, proposed the failure mechanism of the soil layer anchorage:"breakthrough damage, complex control."...