Study On Effect Of Anchorage Length Of Saturated Clay Layer And Engineering Optimization

In recent years,owing to the development and utilization of underground space,the foundation pit engineering and its supporting technology have been developed rapidly.Bolt support is the most common and economical anchorage technology.In the current relevant regulation and technical standards,anchor rod is designed according to the assumption that the shear stress is distributed uniformly along the anchor.Therefore,on the basis of this assumption,when the excavation of the foundation pit is deep,it is necessary to provide a large uplift bearing capacity.But by the late research of many scholars in all aspects confirmed: when the anchor length exceeds a certain value,there are serious discrepancies and fact.There are long bolt of whiplash effect,namely after the long bolt force is little or no,which makes the design exist hidden dangers.Therefore,in order to optimize the design,reduce risks and project cost,the relationship between shear stress distribution and the characteristics of the soil that requires people to further research of the anchor in clay layer,it is very important.According to the demand for the development of Saturated Clay Anchorage theory,and the actual situation of Anchorage design and construction in saturated clay,the study is carried out.Moreover,the study is also based on the subject which is named “Study on length effect of anchorage cable of saturated clay layer and engineering optimization”.The main results of this paper are as follows:(1)The model of Gaussian curves distribution in saturated clay soils is proved reasonable in this dissertation.This conclusion is proved by consulting many conferences,collecting many field pullout test data;(2)The theoretical analysis and mathematical methods is used in this dissertation,aiming to guiding engineering practice;(3)Another conclusion is that there are relationships between shear stress and effective anchorage length(2.22),which is based on the model of Gaussian curves;(4)Taking saturated clay as background,FLAC is used to analyze different anchoring lengths,and the effective length calculating formulas(3.6)is fitted by Origin;(5)The design of anchor rope in foundation pit project of Jinan Municipal ServiceCenter is optimized.The result is that the anchoring length is 10~12m by using equation which is concluded before.This is basically consistent with the effective anchoring length(10~14m)of the fitting formula(origin).Compared with the actual monitoring data,the simulated monitoring data of anchoring length and the optimized method are the same,but the variation tendency is the difference between the two.The above formulas and conclusions have some theoretical and practical significance to guide the construction and production of the similar pile anchor support structure in saturated clay.