發(fā)布時(shí)間：2018-09-07 14:31

【摘要】：CFG樁復(fù)合地基技術(shù)通過二十余年的科研和工程實(shí)踐,從最初應(yīng)用于多層建筑發(fā)展到廣泛應(yīng)用于高層和超高層建筑地基處理,取得了顯著的經(jīng)濟(jì)效益和社會(huì)效益。本文主要完成以下工作： 1.完成模擬高低層連體建筑形成偏心荷載作用的室內(nèi)模型試驗(yàn),獲得軸心荷載作用下天然地基、均勻布樁CFG樁復(fù)合地基基底反力可簡化為均勻分布；偏心荷載作用下天然地基、均勻布樁CFG樁復(fù)合地基基底反力可簡化為線性分布；偏心荷載作用下高層部位均勻布置長樁、低層部位均勻布置短樁的局部均勻布樁CFG樁復(fù)合地基基底反力可簡化為局部均勻分布；“等變形”條件下(本文根據(jù)試驗(yàn)條件,當(dāng)基礎(chǔ)長度方向兩端差異沉降小于某一較小數(shù)值時(shí),即認(rèn)為左右兩端為變形相等的“等變形”狀態(tài))高層部位均勻布置長樁、低層部位均勻布置短樁的局部均勻布樁CFG樁復(fù)合地基,基底反力可簡化為長樁區(qū)域高、短樁區(qū)域低的局部均勻分布,且按高層、低層部位復(fù)合地基的復(fù)合模量進(jìn)行分配。 2.基于以集中力表示的靜力平衡方程,推導(dǎo)了多樁型復(fù)合地基承載力表達(dá)式；指出多樁型復(fù)合地基施工完成后的樁間土承載力提高系數(shù),與土性、施工工藝和樁間距有密切的關(guān)系；提出不同布樁形式下,多樁型復(fù)合地基面積置換率的計(jì)算方法；提出多樁型復(fù)合地基計(jì)算變形時(shí)如何進(jìn)行分區(qū),各分區(qū)復(fù)合模量提高系數(shù)如何計(jì)算,以及如何進(jìn)行分層,各分層復(fù)合模量如何進(jìn)行計(jì)算,并給出多樁型復(fù)合地基變形計(jì)算的步驟；提出不同布樁形式下,多樁型復(fù)合地基的質(zhì)量檢測方法。 3.針對(duì)目前天然地基、CFG樁復(fù)合地基變形計(jì)算中,存在壓縮模量取值不當(dāng)?shù)膯栴},提出對(duì)固結(jié)試驗(yàn)結(jié)果進(jìn)行擬合分析。在綜合分析大量前人研究擬合固結(jié)試驗(yàn)結(jié)果成果的基礎(chǔ)上,提出新的數(shù)學(xué)模型：e=c[exp(aNpbN)-1]+e0 該數(shù)學(xué)模型除具有單調(diào)遞減和呈“S”形的特點(diǎn)外,還滿足邊界條件：當(dāng)壓力p=0時(shí),孔隙比e=e0,為天然孔隙比；當(dāng)壓力p→+∞時(shí),孔隙比e=e0,為壓密極限。本文運(yùn)用最優(yōu)化方法求得的各參數(shù),具有唯一的確定值,并運(yùn)用VC++編制了相關(guān)可視化程序。對(duì)大量固結(jié)試驗(yàn)結(jié)果的擬合分析表明,本文提出的數(shù)學(xué)模型對(duì)固結(jié)試驗(yàn)結(jié)果的擬合程度高,因而可直接運(yùn)用本文提出的數(shù)學(xué)模型對(duì)固結(jié)試驗(yàn)結(jié)果進(jìn)行擬合,可通過編制相關(guān)程序確定自重壓力至自重壓力與附加壓力之和的壓力段的壓縮模量,實(shí)現(xiàn)人機(jī)對(duì)話,避免人為誤差,達(dá)到提高變形計(jì)算精度的目的。
[Abstract]:Through more than 20 years of scientific research and engineering practice, the CFG pile composite foundation technology has been developed from the initial application in multi-storey buildings to the extensive application in the foundation treatment of high-rise and super-high-rise buildings, and has achieved remarkable economic and social benefits. The main work of this paper is as follows: 1. The indoor model test is completed to simulate the eccentric load action of high and low story contiguous building. The natural foundation under axial load is obtained. The reaction force of CFG pile composite foundation can be simplified to uniform distribution, and the natural foundation under eccentric load, The reaction force of CFG pile composite foundation can be reduced to linear distribution. Under the condition of "equal deformation", the reaction force of the CFG pile composite foundation can be simplified as the local uniform distribution under the condition of "equal deformation". When the differential settlement in the direction of foundation length is less than a certain value, that is, it is considered that the two ends of the foundation are equal in deformation "equal deformation") the long piles are uniformly arranged in the upper part of the foundation. The local uniformly distributed pile CFG pile composite foundation with short pile is arranged uniformly in the lower layer. The reaction force of the base can be simplified as the local uniform distribution in the long pile area and the short pile area, and according to the high level, the base reaction force can be reduced to the local uniform distribution in the long pile area and the short pile area. Distribution of composite modulus of composite foundation at low level. 2. Based on the static equilibrium equation expressed by concentrated force, the bearing capacity expression of multi-pile composite foundation is derived, and it is pointed out that the coefficient of soil bearing capacity between piles and soil is improved after the construction of multi-pile composite foundation. The construction technology is closely related to pile spacing, the calculation method of area replacement rate of multi-pile composite foundation under different pile layout forms is put forward, and how to partition the deformation of multi-pile composite foundation is put forward. How to calculate the increasing coefficient of composite modulus, how to delaminate, how to calculate the composite modulus of each layer, and how to calculate the deformation of multi-pile composite foundation are given. Quality testing method of multi-pile composite foundation. 3. In view of the problem of improper compression modulus in the deformation calculation of natural foundation with CFG pile composite foundation at present, the fitting analysis of consolidation test results is put forward. On the basis of synthetically analyzing the results of a large number of previous studies and fitting consolidation tests, a new mathematical model, exp (aNpbN) c [exp (aNpbN) 1] e 0, is proposed, which has the characteristics of monotone decline and "S" shape. It also satisfies the boundary conditions: when the pressure p = 0, the porosity ratio e0 is the natural porosity ratio, and when the pressure p 鈭，

本文編號(hào)：2228535