【正文】 .......................................................................................................................... 4 地基處理方案的分析與優(yōu)選 .................................................................................................. 4 鉆孔灌注樁方案 .......................................................................................................... 4 CFG 樁方案 ................................................................................................................. 4 地基處理方案的選擇 ................................................................................................... 4 3 CFG 樁設(shè)計計算 ............................................................................................................................. 6 設(shè)計依據(jù) .............................................................................................................................. 6 持力層及樁長 ....................................................................................................................... 6 樁徑 ..................................................................................................................................... 6 樁間距 ................................................................................................................................. 6 CFG 復合地基 置換率 ............................................................................................................ 7 樁數(shù) ..................................................................................................................................... 7 單樁豎向承載力特征值 R...................................................................................................... 8 復合地基承載力特征值 ......................................................................................................... 9 混凝土樁體強度設(shè)計 ............................................................................................................ 9 4 變形驗算 ...................................................................................................................................... 11 復合土層的壓縮模量的確定 ................................................................................................. 11 基底平均附加壓力 ............................................................................................................... 11 復合地基沉降計算 ............................................................................................................... 11 5 褥墊層的設(shè)計 ...............................................................................................................................14 褥墊層的設(shè)置 ......................................................................................................................14 褥墊層作用 .........................................................................................................................14 褥墊鋪設(shè) .............................................................................................................................15 6 CFG 樁施工 ...................................................................................................................................16 CFG 樁施工前的設(shè)備 ...........................................................................................................16 施工技術(shù)措施包含以下內(nèi)容 .................................................................................................16 CFG 樁施工流程及技術(shù)要求 ................................................................................................17 采用長螺旋鉆孔、管內(nèi)泵混合料灌注成樁的施工流程 .................................................17 長螺旋鉆孔、管內(nèi)泵壓混合料灌注成樁施工要求 ........................................................18 結(jié) 論 .............................................................................................................................................19 參考文獻 ..........................................................................................................................................20 致 謝 .............................................................................................................................................21 1 緒論 CFG 樁及其復合地基知識概述 CFG 樁 CFG(Cement Flying— ash Gravel pile)樁是在碎石樁樁體中 摻加適量的粉煤灰、石屑或砂、水泥及特種添加劑加水拌合，用各種成樁機械制成的一種高黏結(jié)強度樁體的簡稱。 關(guān)鍵詞： CFG 樁復合地基；地基 承載力；地基變形 Abstract The main purpose of the ground treatment is to improve the strength and control of ground the deformation of ground. The engineering geological conditions is poor and the ground bearing capacity of natural base is not big enough, can be used CFG pile posite foundation reinforced. While CFG pile posite foundation is only developed in recent years, but its speed of construction, building lowcost, adjustable, and the suitability, reliability, and posite foundation settlement small, the current CFG pile posite foundation widely used in many areas. According to the building site geotechnical engineering investigation of the information，this paper analysis and evaluation the engineering geological conditions of the venue and design CFG pile posite foundation. The main elements of the design is effective pile length, pile diameter, pile spacing, covering an area of exchange rates, pile capacity, the bearing capacity of posite foundation, pile material strength, and the settlement and tilt were to ensure the safety of buildings . Keywords: CFG pile posite foundation。 根據(jù)建筑物場地的巖土工程勘察資料，論文對場地工程地質(zhì)條件進行分析和評價和CFG 樁復合地基的設(shè)計。某居民樓 CFG 樁地基加固設(shè)計 摘 要 地基處理的目的主要是提高地基強度和控制地基變形。 CFG 樁復合地基雖說是近些年才發(fā)展起來的，但其施工速度快，建筑成本低，可調(diào)性、適合性、可靠性好，復合地基沉降小，目前 CFG 樁復合地基在許多地區(qū)廣泛應(yīng)用。設(shè)計的主要內(nèi)容有有效樁長，樁徑，樁間距，面積置換率，單樁承載力，復合地基的承載力，樁體材料強度，并對沉降和傾斜進行了驗算，以確保建筑物的安全。 value of subsoil bearmg capaclty。就其功能原理來講屬于地基處理范疇，樁身可在全長范圍內(nèi)受力，和樁基相比，由于CFG 樁可以摻人工業(yè)廢料粉煤灰、不配筋以及充分發(fā)揮樁間土的承載能力，工程造價一般為樁基的 1／ 3— 1／ 2。目前已應(yīng)用于公路建設(shè)的軟基處理、橋涵臺背處理和結(jié)構(gòu)物基底處理工程等項目中。 圖 11 CFG 樁復合地基示意圖 CFG 樁復合地基示意圖其加固機理總體來說就是： 褥墊層受上部基礎(chǔ)荷載作用產(chǎn)生變形后以一定的比例將荷載分攤給樁及樁間土，使二者共同受力。由于樁體的強度和模量比樁間土大，在荷載作用下，樁頂應(yīng)力比樁間土表面應(yīng)力大。這樣，由