黏性土地区桩基承载力与桩径关系的现场试验研究 -土木工程专业

摘要

桩基承载力与桩径关系的研究在土木工程领域具有重要意义，尤其是在黏性土地区。随着基础设施建设向复杂地质条件扩展，深入理解桩基承载特性成为关键科学问题。本研究以黏性土地区的实际工程为背景，通过现场静载试验和钻孔取样分析，系统探讨了不同桩径条件下桩基承载力的变化规律及其影响机制。研究选取了直径范围为0.6m至1.2m的预制桩作为试验对象，结合土体力学参数测试，建立了桩径与承载力之间的定量关系模型。结果表明，桩径增大对桩端阻力和桩侧摩阻力均有显著影响，且两者随桩径变化的规律呈现非线性特征。进一步分析发现，黏性土的天然含水率和灵敏度是控制桩基承载力的重要因素。本研究创新性地提出了基于土体结构性特性的修正模型，能够更准确地预测大直径桩的承载能力。该模型较传统方法具有更高的精度，为黏性土地区桩基设计提供了理论支持和技术参考，同时为优化桩基选型和降低工程成本奠定了基础。研究成果对提升桩基工程的安全性和经济性具有重要实践价值。

关键词：桩基承载力；黏性土；桩径效应；非线性关系；土体结构性特性

ABSTRACT

The study of the relationship between pile bearing capacity and pile diameter is of great significance in civil engineering, particularly in clayey soil regions. As infrastructure construction expands into complex geological conditions, a deeper understanding of pile bearing characteristics has become a critical scientific issue. This research, based on actual engineering projects in clayey soil areas, systematically investigates the variation patterns and influencing mechanisms of pile bearing capacity under different pile diameters through field static load tests and borehole sampling analyses. Prefabricated piles with diameters ranging from 0.6m to 1.2m were selected as test subjects, and a quantitative relationship model linking pile diameter and bearing capacity was established by combining soil mechanics parameter tests. The results indicate that an increase in pile diameter significantly affects both the end-bearing resistance and the side frictional resistance, with their variations exhibiting nonlinear characteristics. Further analysis reveals that the natural water content and sensitivity of clayey soils are key factors controlling pile bearing capacity. Innovatively, this study proposes a modified model based on the structural characteristics of soil, which can more accurately predict the bearing capacity of large-diameter piles. Compared with traditional methods, the proposed model demonstrates higher accuracy, providing theoretical support and technical references for pile foundation design in clayey soil regions. It also lays the foundation for optimizing pile selection and reducing engineering costs. The research findings hold important practical value for enhancing both the safety and economy of pile foundation engineering.

Keywords: Pile Foundation Bearing Capacity; Cohesive Soil; Pile Diameter Effect; Nonlinear Relationship; Soil Structural Properties

摘要 I

ABSTRACT II

第1章绪论 1

1.1 黏性土地区桩基研究背景与意义 1

1.2 国内外研究现状分析 1

1.3 研究方法与技术路线 2

第2章黏性土地区桩基承载力理论基础 3

2.1 黏性土的工程特性概述 3

2.2 桩基承载力的基本原理 3

2.3 桩径对承载力的影响机制 4

第3章现场试验设计与实施 5