Study On Working State Evaluation Methods And Strengthening Technical Of Highway Anti-slide Pile After Earthquake

Artificial drilled pile is a kind of retaining structures developed in our country. It has several prominent advantages, such as, the strong anti-sliding ability, the wide applicability, difficult to worsen landslide state, safe and convenient construction, further verified geological conditions, meanwhile, can be used together with other slope measures flexibly. So far, it has been the most engineering structures applied in landslide treatment.But, in recent years, anti-slide pile in the work appears instability and invalidation. Especially, earthquake and other sudden factors to cause of pile damage and failure affected the stability of reinforced slope. Therefore, analyze and evaluate that anti-slide pile in use process can produce effect normally, relates to the safe project of anti-slide pile, the assessment of working anti-slide pile after the earthquake condition is particularly important. This paper relies on the west traffic construction science and technology project—"Study on security inspection appraisal and repair reinforcement technology of the highway roadbed, slope and retaining structure after earthquake ".The paper mainly does the following job:①According to the domestic and foreign relevant material and investigating highway site in the disaster area after wenchuan earthquake, the common disease type in the highway anti-slide pile has been summarized. Combined with a specific engineering example, this article analyzes the reasons of anti-slide pile disease.②Theoretical analysis of the influence factors with pile in working status, uses the Lizheng geotechnical software to calculate and analyze that different pile length, anchorage depth and concrete strength affect the internal force of anti-slide pile.③Analyse two widely nondestructive testing methods of anti-slide pile, one is low strain reflected wave method and the other is acoustic wave transmission method, and this paper analyzes their advantages and disadvantages, detecting classified standard and the matters needing attention.④After earthquake injure, highway anti-slide pile has been simulated by FLAC3D,in order to analyze the effect on the stability of the overall slope.Through the research make the following progress:①The common disease type in the highway anti-slide pile: the body of pile be cut off or broken, the overrun displacement on the top of pile, the bearing capacity of pile's lateral shortage, more top, soil arching effect failure between the two piles, the overall instability deformation.②The factors put the influence on the pile's working state: horizontal load, the pile length, pile body completeness, reinforcing cage length and corrosion degree, the strength of concrete, the earthquake, etc③Low strain reflection wave method exists tow problem: large diameter pile size effect and rock-socketed piles fluctuations dissipates. Acoustic wave transmission method gets results more accurately than the former one, but need to bury testing tube in advance of the construction.④Using slope safety coefficients as evaluation indexes, the whole working status of pile is evaluated and graded. Numerical analysis shows that the degree of damage is up to 40%, and great impact on anti-slide pile's working state. When damage degree is up to 50%, the slope safety coefficient indicates that anti-slide pile is close to totally destroyed and has no repair necessary.⑤According to different diseases of anti-slide pile and puts forward the corresponding treatment. For example, adding prestressed anchor, adding prestressed anchor frame, GangHua tube grouting, adding pile, drainage measures between piles, etc.This paper studies for future similar can be natural disasters, after-disaster reconstruction work provide certain guidance and technical means.