Analysis Of The Design Parameters On The Horizontal Mechanical Performance Impact Of The Long-short Pile Founation In The Collapsible Loess Foundation

To meet the demand for road and rail operators to improve load levels and associatedbuilding works,on the foundation engineering consolidation processs of the existing bridge,building structures and other buildings. In order to satisfy the requirements of foundationbearing capacity and settlement, the longer and larger piles diameter piles are often added forreinforcing the pile foundation. Thus the new longer piles are work together with the originalshort pile, Due to the reinforcement piles are generally longer, larger pile diameter than theoriginal piles, inevitably appear different types pile coexist in the foundation, This isong-short pile foundation.also at present,the research on it in domestic and foreign are veryfew and the calculation method and design theory have not come into being,this bring muchdifficult to the design and calculation of the pile reinforcement project. it is necessary to studyits bearing properties.For the long-short pile foundation, the difference of the pile length,the variability in thesize of the pile diameter and the size of the pile spacing possiblity have different influence toits load mechanical performance. In order to understand the bearing behavior of this kind ofnew form pilefoundation, in this paper, using numerical simulation method, analysis anddiscuss the horizontal load carrying performance the long and short pile foundation inhomogeneous Loess before and after flooded. the main work completed are:(1) On the basis of relevant literature data, characteristics and force analysis methods,principles, current research of horizontal mechanical performance were reviewed; on thecombination of the length of the pile of features and performance levels of stress analysismethods, principles, current research were reviewed;and combined with design problemsandof the long and short pile encountered in the added piles foundation reinforcement, putsforward the research target of this article.(2) Combined with soil constitutive model based on the analysis of the long and shortpile, determine the displacement function and isoparametric elements in finite elementnumerical simulati.(3) Analyzed the mechanical Performance of the long and short pile under different pilenumber, pile length, pile diameter, pile distance and other conditions, investigated the effectsof the relevant design parameters on its bearing performance; and analyzed and comparedthe pile bearing capacity changes before and after soaking。the results showed that:①By the analysis of pile mechanical performance under the different loads, theinternal forces and displacement values of Its top of the pile are in good agreement withtheoretical calculations, verify the correctness and rationality of the model calculation andanalysis ②By analyzing the pile mechanical performance of the different long pile length, pilespacing, pile diameter, number of piles pile, get the influence of different lengths, pile spacing,pile diameter, pile under on horizontal mechanical performance; For the base model,determine a reasonable complement programs of pile length, pile spacing, pile diameter andpile number.③By simulating and analyzing the changer of topsoil’s parameters before and aftersoaking, investigated the changes of pile bearing capacityb before and after soaking in loessregion. proposed corresponding construction requirements and management recommendations...