Reinforcement Mechanism Of Deep Super Strong Concrete Composite Foundation In Hole And Its Application In Municipal Roads

With the acceleration of the urbanization process,the expansion of the city scale and the construction waste generated by the shanty towns in the city and the renovation of the old urban areas have formed large-scale mixed fillings.On the basis of this,the depth and difficulty of the foundation treatment of municipal road construction is getting larger and larger.The existing mature filling construction method has a shallow depth of treatment,and the replacement treatment not only increases the construction cost but also causes secondary pollution.The deep super-strong method in the hole shows unique engineering and economic advantages when dealing with this problem.After the treatment,it not only meets the requirements of municipal road construction and later operation,but also saves cost and avoids the transportation of garbage.And secondary pollution to the environment.Therefore,the research on the treatment of municipal road foundation by deep super-strong method in the hole not only has practical engineering construction significance,but also has good social value and economic benefits.In this paper,the reinforcement mechanism of single-pile and pile-pile composite foundation with deep super-strong boring method in the hole is studied,and the influencing factors of bearing capacity of single pile and composite foundation are classified and summarized.Based on Vesic’s theory of circular hole expansion,the influence radius of the plastic zone of the ram is obtained when forming the hole and forming the pile.Using the calculation formula of the ultimate bearing capacity of the single pile and the calculation formula of the soil bearing capacity between the Skempton piles,the ultimate bearing of the composite foundation is given.force.The ABAQUS finite element software was used to simulate the deep super-strong boring method in the hole.The effects of different pile soils,different pile soils,different pile diameters,different pile lengths and different pile end soils on the bearing capacity of single pile were analyzed.The bearing mechanism deformation characteristics;compared with natural foundation and group pile composite deformation characteristics;compared with natural foundation and group pile composite foundation under the action of roadbed filling and pavement structure layer gravity,and the influence of cushion and pile spacing on road settlement.Through the on-site test of the municipal project Checheng West Road,the bearing capacity,compactness and uniformity of the composite foundation are tested to further verify the feasibility of the method to deal with the large and complex landfill of urban roads.