长短桩复合地基作为一种较为新型的地基处理技术，凭借其效果显著、多样化选

As a relatively new type of foundation treatment technology, long-short-pile composite foundation has been widely used in practical engineering due to its remarkable effects, diversified choices and good economic benefits. At the same time, more and more scholars have also started to use it in practical engineering. Research on load-bearing properties and mechanism of action. However, its calculation theory is still in the development stage, the actual engineering experience has not accumulated enough, the bearing capacity and settlement calculation methods are not mature enough, and more in-depth research is needed. This paper relies on an engineering example of a rigid and flexible long-short-pile composite foundation in Xingtai City, combined with finite element software for simulation analysis, and mainly does the following work: <br>(1) The basic concept and reinforcement mechanism of the long-short-pile composite foundation are introduced, and The research status and related results are summarized. <br>(2) In-depth analysis of the relevant theories of rigid and flexible long-short-pile composite foundations, covering the following content: cushion layer design, bearing capacity and settlement calculation, which is convenient for direct use in actual engineering design. <br>(3) Construct a simulation analysis model with the aid of ABAQUS finite element software, and then compare the actual static load test results to evaluate the correctness of the model. Combined with the simulation results, the mechanical behavior of the rigid-flexible long-short-pile composite foundation under different load values ​​is analyzed, including changes in settlement, stress distribution between long and short piles, and changes in the pile-soil stress ratio between long and short piles. law. <br>(4) Adjust the pile length and deformation modulus of the long and short piles, as well as the cushion layer thickness, modulus and other parameters based on the application in the actual project, and deeply analyze the influence of the above parameter changes on the settlement of the rigid and flexible long and short pile composite foundation. , The impact of load sharing, and analysis and summary, while reflecting the importance of the cushion layer. <br>The results of this paper have certain reference significance for the design and optimization of similar projects.

As a relatively new foundation treatment technology, the long and short pile compound foundation has been widely used in practical engineering by virtue of its remarkable effect, diversified selection and good economic benefits, and more and more scholars have also carried out research on its carrying features, action structure and so on. However, its computational theory is still in the development stage, the actual engineering experience is not accumulated enough, the carrying capacity and subsidon calculation method is not mature enough, and needs more in-depth research. This paper relies on the engineering example of a rigid flexible long pile composite foundation in Yantai City, and combines the simulation analysis with finite metadata software, mainly doing the following work:<br>(1) The basic concept and reinforcement structure of the long and short pile composite foundation are introduced, and the research status quo and related achievements are summarized.<br>(2) The theory of rigid flexible long pile composite foundation is analyzed in depth, which covers the following contents: the design, carrying capacity and semoulation of the mat layer are calculated, which is convenient for direct use in the actual engineering design.<br>(3) The simulation analysis model is constructed with the help of ABAQUS finite metadata software, and then the results of the actual static load test are compared to evaluate the correctness of the model. Combined with the results of the simulation, the force characteristics of the composite foundation of the rigid flexible long pile under different load values are analyzed, including the change of the amount of subsidion, the stress distribution of the long pile and the short pile, and the change law of the pile-soil stress ratio of the long pile and the short pile.<br>(4) Combined with the application of the actual project, adjust the pile length and deformation mould of the long pile and the short pile, as well as the thickness of the cushion layer, the mod and other parameters, in-depth analysis of the above parameter changes on the rigid flexible long pile composite foundation subsidon, load sharing, and analysis and summary, while reflecting the importance of the mat layer role.<br>The results of this paper have some reference significance for the design and optimization of similar projects.

As a new foundation treatment technology, long short pile composite foundation has been widely used in practical engineering with its remarkable effect, diversified selection and good economic benefits. At the same time, more and more scholars have also carried out research on its bearing behavior and mechanism. However, its calculation theory is still in the development stage, the actual engineering experience is not enough, the bearing capacity and settlement calculation method is not mature enough, so it needs to be further studied. In this paper, based on the engineering example of a rigid flexible long short pile composite foundation in Xingtai City, and combining with the finite element software, the simulation analysis is carried out<br>(1) This paper introduces the basic concept and reinforcement mechanism of long short pile composite foundation, and summarizes the research status and related achievements.<br>(2) In this paper, the related theories of rigid flexible long short pile composite foundation are deeply analyzed, including the following contents: cushion design, bearing capacity and settlement calculation, which are convenient for direct use in practical engineering design.<br>(3) With ABAQUS finite element software, the simulation analysis model is constructed, and then the actual static load test results are compared to evaluate the correctness of the model. Combined with the simulation results, the mechanical behavior of rigid flexible long short pile composite foundation under different load values is analyzed, including the change of settlement, the stress distribution of long pile and short pile, and the variation law of pile-soil stress ratio of long pile and short pile.<br>(4) Combined with the application of practical engineering, the pile length and deformation modulus of long pile and short pile, as well as the thickness and modulus of cushion layer are adjusted. The influence of the above parameters on the settlement and load sharing of rigid flexible long short pile composite foundation is analyzed and summarized. At the same time, the importance of cushion layer is reflected.<br>The results of this paper have a certain reference significance for the design and optimization of similar projects.<br>