本研究旨在探究鈣質(zhì)砂中樁的水平承載特性。通過模型樁試驗(yàn)研究樁頭固定條件對樁承載特性的影響以及樁側(cè)注漿對樁基承載潛力的增強(qiáng)作用,試驗(yàn)采用的鈣質(zhì)砂來自中國南沙群島。研究的重點(diǎn)在于:樁側(cè)注漿前后試樁的最大水平承載力,試樁達(dá)到極限承載力時(shí)對應(yīng)的土體變形,水泥漿液的壓注過程參數(shù)以及水泥漿泡的尺寸和厚度。研制出了一套新型注漿裝置來實(shí)現(xiàn)對試樁的樁側(cè)注漿,該裝置在注漿時(shí)可以控制注漿壓力;水泥漿液通過設(shè)置在試樁內(nèi)部的兩根注漿管經(jīng)注漿孔注入樁側(cè)土層,注漿孔在試樁上部,與樁頭的距離為樁長的三分之一。在正式試驗(yàn)之前進(jìn)行了幾次試注漿,目的是為了優(yōu)化注漿步驟并大致確定正式試驗(yàn)時(shí)需要的注漿壓力,為減少鈣質(zhì)砂損耗,試注漿在與試驗(yàn)用的鈣質(zhì)砂顆粒級配相近的石英砂中進(jìn)行。在試注漿過程中發(fā)現(xiàn):若采用實(shí)際工程中的普通硅酸鹽水泥漿液,水泥會在注漿過程中堵塞注漿管。其原因可能是模型樁的尺寸較小,實(shí)際工程中采用的注漿水泥粒徑對于模型樁來說過大,將普通硅酸鹽水泥更換為平均粒徑為5微米的超細(xì)水泥后試注漿堵管問題得到了解決,遂在正式試驗(yàn)中采用超細(xì)水泥漿液。按照ASTM D3966加載方案,通過在樁頭處逐漸施加水平荷載來測試試樁的極限承載力... 

【文章頁數(shù)】：94 頁

【學(xué)位級別】：碩士

【文章目錄】：
Acknowledgements
摘要
Abstract
CHAPTER 1: BACKGROUND AND LITERATURE REVIEW
    1.1 INTRODUCTION
    1.2 PROPERTIES OF CALCAREOUS SAND
        1.2.1 Classification of Calcareous deposits
        1.2.2 Bulk And Individual Grains Physical Properties
        1.2.3 Calcareous sediments engineering properties
    1.3 PILES FOUNDATION AXIAL CAPACITY IN CALCAREOUS SAND
        1.3.1 Skin Friction
        1.3.2 End Bearing
    1.4 PILES FOUNDATION LATERAL CAPACITY IN CALCAREOUS SAND
        1.4.1 Exisiting analytical approaches to predict laterally loaded pile behavior
        1.4.2 Experimental and analytical studies concern about piles embedded in calcareous sand
        1.4.3 Finite element analysis
        1.4.4 Grouting and cementation influences
    1.5 RESEARCH OBJECTIVES
    1.6 THESIS STRUCTURE
CHAPTER 2: PILE LATERAL LOAD TEST IN VIRGIN SOIL EXPERIMENTAL INVESTIGATION
    2.1 INTRODUCTION
    2.2 TEST LAYOUT AND PREPARATION
        2.2.1 Test layout
        2.2.2 Materials specifications
        2.2.3 Measurements and instrumentation
    2.3 TEST PROCEDURE
    2.4 TEST RESULTS
        2.4.1 Free Head condition
        2.4.2 Fixed head condition
    2.5 SUMMARY
CHAPTER 3: EXPERIMENTAL INVESTIGATION OF PILE POST GROUTING INFLUENCE
    3.1 INTRODUCTION
    3.2 TEST LAYOUT AND PREPARATION
        3.2.1 Test layout
        3.2.2 Materials specifications
        3.2.3 Grout injection equipment
        3.2.4 Measurements and instrumentation
    3.3 TEST PROCEDURE
    3.4 TEST RESULTS
        3.4.1 Free Head condition
        3.4.2 Fixed head condition
        3.4.3 General remarks of test results
    3.5 SUMMARY
CHAPTER 4: INTERPRETATION AND NUMERICAL MODELLING OF EXPERIMENTAL RESULTS
    4.1 INTRODUCTION
    4.2 ANALYTICAL REMARKS
    4.3 FINITE ELEMENT MODELING
    4.4 SUMMARY
CHAPTER 5: CONCLUSIONS AND FUTURE RESEARCH
    5.1 INTRODUCTION
    5.2 CONCLUSIONS
        5.2.1 Virgin Soil condition experimental investigation findings
        5.2.2 Post grouted piles experimental investigation findings
        5.2.3 Grout Injection process findings
    5.3 RECOMMENDATIONS FOR FUTURE RESEARCH
REFERENCES



本文編號：3701972