既有多层建筑旋喷桩地基加固与掏土纠偏技术应用研究 专 业：建筑与土木工

既有多层建筑旋喷桩地基加固与掏土纠偏技术应用研究<br> 专 业：建筑与土木工程<br>硕 士 生：李英驰<br>指导教师：黄莺 王建平<br>摘要<br>目前既有多层建筑地基加固与纠偏的设计方案往往选择静压托换桩与掏土纠偏的组合施工策略，运用此策略有效阻止了建筑物的不均匀沉降并达到了纠倾的目的。这是因为需要进行地基加固与纠倾的建筑物大多采用条形基础，而条形基础形式的建筑物室内室外均有利于导坑的开挖，静压托换桩加固技术就是充分利用条形基础的这个特点，达到了施工快、见效早，托换完成后还具有一定的顶升作用，缩小上部建筑的沉降裂缝。然而，对于钢筋混凝土筏板基础形式多层建筑的加固纠偏工程，继续采用静压托换桩加固法会大大增加导坑开挖的工作量。<br>本文针对筏板基础形式的既有多层建筑的加固纠偏工程，提出采用旋喷桩地基加固技术与掏土纠偏技术相互结合方案，对倾斜建筑的地基基础进行加固纠偏处理。论文以宝鸡市太白·桃园9#楼地基加固与纠偏工程为背景，详细分析了该方案的基本原理、设计思路和施工工艺，利用有限元软件分析了旋喷桩加固过程和掏土纠偏施工引起地基的变形规律，并对旋喷桩施工方案进行了优化，主要内容如下：<br>（1）系统阐述了国内外既有建筑地基加固及纠倾研究现状，从地质灾害、勘察设计、周围环境影响、施工、管理及后期使用不当等角度，分析建筑物出现倾斜事故的原因。<br>（2）探究目前事故处理中常用的地基加固方法中石灰桩法、旋喷桩加固法、桩式托换法以及化学加固法各自的特点及适用范围，通过以上几种加固方法的比较分析，结合该建筑物的基础形式、地基处理方法、变形特点及土质情况，选择出最适合本工程的加固纠倾方案。<br>（3）研究掏土纠倾的基本原理，根据圆筒形扩孔理论指导分析导坑水平掏土引起地基土体的挤压变形情况，通过数值模拟探究掏土纠偏中基底土体面积削弱率对上部建筑沉降的影响情况，进而指导实际工程中掏土纠偏工作进展。<br>（4）系统的分析旋喷桩地基基础加固理论知识，运用MIDAS-GTS有限元软件，模拟分析本工程旋喷桩施工对地基产生最小附加沉降情况下的最优桩长、桩径、桩间距，改善现有多层建筑结构地基基础加固工程旋喷桩加固施工方案以降低其对地基沉降的影响，以达到更好的工程加固效果。<br>（5）结合太白·桃园9#楼地基加固与纠偏工程，运用旋喷桩地基加固技术与掏土纠偏技术相互结合的方案，成功的将建筑物的最大倾斜率由5.49‰恢复至2.50‰，同时改良地基土质，大大提高了地基的防渗性能。最后通过施工过程监测和完工后复检，得出该楼整体加固纠偏效果良好的结论，验证旋喷桩地基加固技术与掏土纠偏技术相互结合可行性。<br>关键词：既有多层建筑；旋喷桩；掏土纠偏；筏板基础；附加沉降<br>论文类型：应用研究

既有多层建筑旋喷桩地基加固与掏土纠偏技术应用研究<br> 专 业：建筑与土木工程<br>硕 士 生：李英驰<br>指导教师：黄莺 王建平<br>摘要<br>目前既有多层建筑地基加固与纠偏的设计方案往往选择静压托换桩与掏土纠偏的组合施工策略，运用此策略有效阻止了建筑物的不均匀沉降并达到了纠倾的目的。 这是因为需要进行地基加固与纠倾的建筑物大多采用条形基础，而条形基础形式的建筑物室内室外均有利于导坑的开挖，静压托换桩加固技术就是充分利用条形基础的这个特点，达到了施工快、见效早，托换完成后还具有一定的顶升作用，缩小上部建筑的沉降裂缝。 然而，对于钢筋混凝土筏板基础形式多层建筑的加固纠偏工程，继续采用静压托换桩加固法会大大增加导坑开挖的工作量。<br>本文针对筏板基础形式的既有多层建筑的加固纠偏工程，提出采用旋喷桩地基加固技术与掏土纠偏技术相互结合方案，对倾斜建筑的地基基础进行加固纠偏处理。 论文以宝鸡市太白·桃园9#楼地基加固与纠偏工程为背景，详细分析了该方案的基本原理、设计思路和施工工艺，利用有限元软件分析了旋喷桩加固过程和掏土纠偏施工引起地基的变形规律，并对旋喷桩施工方案进行了优化，主要内容如下：<br>（1）系统阐述了国内外既有建筑地基加固及纠倾研究现状，从地质灾害、勘察设计、周围环境影响、施工、管理及后期使用不当等角度，分析建筑物出现倾斜事故的原因。<br>（2）探究目前事故处理中常用的地基加固方法中石灰桩法、旋喷桩加固法、桩式托换法以及化学加固法各自的特点及适用范围，通过以上几种加固方法的比较分析，结合该建筑物的基础形式、地基处理方法、变形特点及土质情况，选择出最适合本工程的加固纠倾方案。<br>（3）研究掏土纠倾的基本原理，根据圆筒形扩孔理论指导分析导坑水平掏土引起地基土体的挤压变形情况，通过数值模拟探究掏土纠偏中基底土体面积削弱率对上部建筑沉降的影响情况，进而指导实际工程中掏土纠偏工作进展。<br>（4）系统的分析旋喷桩地基基础加固理论知识，运用MIDAS-GTS有限元软件，模拟分析本工程旋喷桩施工对地基产生最小附加沉降情况下的最优桩长、桩径、桩间距，改善现有多层建筑结构地基基础加固工程旋喷桩加固施工方案以降低其对地基沉降的影响，以达到更好的工程加固效果。<br>（5）结合太白·桃园9#楼地基加固与纠偏工程，运用旋喷桩地基加固技术与掏土纠偏技术相互结合的方案，成功的将建筑物的最大倾斜率由5.49‰恢复至2.50‰，同时改良地基土质，大大提高了地基的防渗性能。 最后通过施工过程监测和完工后复检，得出该楼整体加固纠偏效果良好的结论，验证旋喷桩地基加固技术与掏土纠偏技术相互结合可行性。<br>关键词：既有多层建筑；旋喷桩；掏土纠偏；筏板基础；附加沉降<br>论文类型：应用研究

Study on the application of rotary jet grouting pile foundation reinforcement and soil digging rectification technology in existing multi-storey buildings<br>Major: Architecture and civil engineering<br>Master student: Li Yingchi<br>Instructor: Huang Ying, Wang Jianping<br>abstract<br>At present, the combination construction strategy of static pressure underpinning pile and digging soil is often selected in the design scheme of foundation reinforcement and rectification of existing multi-storey buildings, which effectively prevents the uneven settlement of buildings and achieves the purpose of rectification. This is because most of the buildings that need to be reinforced and corrected are based on strip foundation, while the indoor and outdoor buildings with strip foundation form are conducive to the excavation of the heading. The static pressure underpinning pile reinforcement technology is to make full use of the characteristics of strip foundation, which has achieved rapid construction and early effect. After underpinning, it also has a certain jacking effect, reducing the settlement cracks of the upper building 。 However, for the reinforced concrete raft foundation form of multi-storey building reinforcement and rectification project, continue to use static pressure underpinning pile reinforcement method will greatly increase the workload of heading excavation.<br>In this paper, aiming at the reinforcement and rectification project of existing multi-storey building with raft foundation, a scheme of combining the foundation reinforcement technology of rotary jet grouting pile with the deviation rectification technology of digging soil is proposed to reinforce and rectify the foundation of inclined building. Based on the foundation reinforcement and rectification project of Taibai Taoyuan 9th floor in Baoji City, this paper analyzes the basic principle, design idea and construction technology of the scheme in detail, analyzes the deformation law of the foundation caused by the reinforcement process of rotary jet grouting pile and the rectification construction of digging soil by using the finite element software, and optimizes the construction scheme of rotary jet grouting pile, the main contents are as follows:<br>(1) This paper systematically expounds the research status of foundation reinforcement and rectification of existing buildings at home and abroad, and analyzes the causes of building inclination accidents from the perspectives of geological disasters, survey and design, environmental impact, construction, management and improper use in the later period.<br>(2) This paper explores the characteristics and scope of application of lime pile method, rotary jet grouting pile method, pile underpinning method and chemical reinforcement method, which are commonly used in accident treatment. Based on the comparative analysis of the above reinforcement methods, combined with the foundation form, foundation treatment method, deformation characteristics and soil conditions of the building, the most suitable reinforcement and correction method is selected Case.<br>(3) This paper studies the basic principle of digging and rectification, analyzes the squeezing deformation of foundation soil caused by horizontal digging of heading according to the theory of cylindrical hole expansion, and probes into the influence of the weakening rate of base soil area on the settlement of superstructure in digging and rectification through numerical simulation, so as to guide the progress of digging and rectification in practical engineering.<br>(4) Based on the systematic analysis of the theoretical knowledge of the foundation reinforcement of rotary jet grouting pile, the midas-gts finite element software is used to simulate and analyze the optimal pile length, pile diameter and pile spacing under the condition that the construction of rotary jet grouting pile produces the minimum additional settlement to the foundation, so as to improve the construction scheme of the foundation reinforcement of existing multi-storey building structure to reduce its impact on the foundation settlement, so as to achieve better results Strengthening effect of the project.<br>(5) Combined with the foundation reinforcement and rectification project of Taibai Taoyuan No.9 building, the scheme of combining the foundation reinforcement technology of rotary jet grouting pile with the deviation rectification technology of digging soil is used to successfully recover the maximum inclination rate of the building from 5.49 ‰ to 2.50 ‰. Meanwhile, the soil quality of the foundation is improved, which greatly improves the impermeability of the foundation. Finally, through the monitoring of the construction process and the re inspection after completion, the conclusion that the overall reinforcement and rectification effect of the building is good is obtained, and the feasibility of the combination of the foundation reinforcement technology of rotary jet grouting pile and the rectification technology of digging soil is verified.<br>Key words: existing multi-storey building; rotary jet grouting pile; soil digging and deviation correction; raft foundation; additional settlement<br>Paper type: Applied Research<br>