岩溶强发育地区深桩基础施工关键技术研究
发布时间：2018-07-26 13:31
【摘要】：沪昆客专长昆湖南段CKTJ-2标一分部所属工程位于石灰岩岩溶强发育地区,其桥梁基础均采用深桩结构,岩溶强发育给施工带来较大度的技术难度：最深的基桩达126m,最大的溶洞跨度达60m,穿越层数最多的串洞达10层,本文结合工程建设的需要和笔者的工作需要,从技术、质量、经济、成桩效率等方面分析研究岩溶强发育地区深桩基础施工技术,总结施工经验和注意事项,主要工作和创新点有： 1.在岩溶强发育底层普遍、深桩大量采用的工程区域,针对仅依靠孔内土自造泥浆的传统工艺缺点：泥浆悬浮功能差、出渣困难、制约钻进效率、甚至不能起到良好的护壁作用；提出了采用膨润土、聚丙烯酰胺、纤维素等几种材料造浆壁技术,通过试验得出合理配合比。 2.一般情况下遇溶洞泥浆液面下降时,一般采用通过片石加粘土填充溶洞,达到保证泥浆水头的效果；但在遇到裂隙的情况下,特别是与裂隙连通的另一个溶洞较大的情况下,单纯采用片石加黏土、或者水泥、甚至混凝土的措施都效果不佳,对此,本文提出了采用(粘土+麻绳)／(水泥+麻绳)再抛填的方法进行堵漏。 3.针对背景工程岩溶强发育区地质情况复杂多变,提出了对溶洞进行预处理的方法,即分别采用注浆加固法(双浆液)、压浆法、灌砂法、超前钻孔灌注混凝土法对溶洞进行预处理,通过预处理大大降低了钻孔过程中泥浆流失、塌孔等质量问题的发生频率。 4.开发专用钢筋笼加工胎具及钢筋笼下放吊具,用以减少钢筋笼下放过程中对溶洞的扰动和保证钢筋笼的垂直度。 5.提出了在钢筋笼上溶洞位置安装100目的铁纱网技术,防止岩溶深桩混凝土灌注过程中混凝土挤塌溶洞壁。 本文提出的技术和方法可为同类工程借鉴。
[Abstract]:The project belonging to the first sub-division of CKTJ-2, which specializes in Hunan section of Hukunke, is located in the area where limestone karst is strong, and its bridge foundation adopts deep pile structure. The strong development of karst brings great technical difficulty to the construction: the deepest foundation pile is 126m, the largest karst cave span is 60m, the number of layers through the most serial holes is 10 stories. This paper combines the needs of the project construction and the author's work needs, from the technology, the quality, This paper analyzes and studies the construction technology of deep pile foundation in karst strong development area from the aspects of economy and pile forming efficiency, summarizes the construction experience and points for attention. The main work and innovations are as follows: 1. In the engineering area where deep piles are widely used in deep piles, the traditional technology shortcomings of mud self-made only by hole soil are: poor suspension function of mud, difficult slag production, restricted drilling efficiency, and even can not play a good role in wall protection; Bentonite, polyacrylamide, cellulose and other materials were used to make slurry wall technology, and the reasonable mix ratio was obtained by experiment. Generally speaking, when the slurry level of the cavern drops, the cavern is usually filled with flakes and clay to ensure the mud head, but in the case of a fissure, especially in the case of a larger cavern connected with the fissure, The simple use of flake stone with clay, cement, or even concrete is not effective. In this paper, the method of (clay hemp rope) / (cement hemp rope) is put forward to plug the leakage. 3. In view of the complex and changeable geological conditions of karst strong development area in background engineering, the pretreatment method of karst cave is put forward, that is, grouting reinforcement method (double grouting method), grouting method and sand pouring method, respectively. In this paper, the preprocessing of the cavern is carried out by the method of ahead drilling and pouring concrete, and the frequency of the quality problems such as mud loss and hole collapse in the drilling process is greatly reduced by the pretreatment. 4. In order to reduce the disturbance to the cavern and ensure the perpendicularity of the steel cage during the process of rebar cage dewatering, the special rebar cage processing placer and the rebar cage lower hanger are developed to ensure the perpendicularity of the reinforcement cage. In order to prevent concrete from collapsing into the wall of karst deep pile concrete during the pouring process, the technology of installing 100 purpose iron mesh in the position of karst cavern on the reinforcement cage is put forward in this paper. The techniques and methods presented in this paper can be used for reference by similar projects.
【学位授予单位】：中南大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U445.551
本文编号：2146166
[Abstract]:The project belonging to the first sub-division of CKTJ-2, which specializes in Hunan section of Hukunke, is located in the area where limestone karst is strong, and its bridge foundation adopts deep pile structure. The strong development of karst brings great technical difficulty to the construction: the deepest foundation pile is 126m, the largest karst cave span is 60m, the number of layers through the most serial holes is 10 stories. This paper combines the needs of the project construction and the author's work needs, from the technology, the quality, This paper analyzes and studies the construction technology of deep pile foundation in karst strong development area from the aspects of economy and pile forming efficiency, summarizes the construction experience and points for attention. The main work and innovations are as follows: 1. In the engineering area where deep piles are widely used in deep piles, the traditional technology shortcomings of mud self-made only by hole soil are: poor suspension function of mud, difficult slag production, restricted drilling efficiency, and even can not play a good role in wall protection; Bentonite, polyacrylamide, cellulose and other materials were used to make slurry wall technology, and the reasonable mix ratio was obtained by experiment. Generally speaking, when the slurry level of the cavern drops, the cavern is usually filled with flakes and clay to ensure the mud head, but in the case of a fissure, especially in the case of a larger cavern connected with the fissure, The simple use of flake stone with clay, cement, or even concrete is not effective. In this paper, the method of (clay hemp rope) / (cement hemp rope) is put forward to plug the leakage. 3. In view of the complex and changeable geological conditions of karst strong development area in background engineering, the pretreatment method of karst cave is put forward, that is, grouting reinforcement method (double grouting method), grouting method and sand pouring method, respectively. In this paper, the preprocessing of the cavern is carried out by the method of ahead drilling and pouring concrete, and the frequency of the quality problems such as mud loss and hole collapse in the drilling process is greatly reduced by the pretreatment. 4. In order to reduce the disturbance to the cavern and ensure the perpendicularity of the steel cage during the process of rebar cage dewatering, the special rebar cage processing placer and the rebar cage lower hanger are developed to ensure the perpendicularity of the reinforcement cage. In order to prevent concrete from collapsing into the wall of karst deep pile concrete during the pouring process, the technology of installing 100 purpose iron mesh in the position of karst cavern on the reinforcement cage is put forward in this paper. The techniques and methods presented in this paper can be used for reference by similar projects.
【学位授予单位】：中南大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U445.551
【参考文献】
相关期刊论文 前10条
1 姜明和;桩基施工中岩溶地质危害的治理[J];地质与勘探;2000年02期
2 王革立;宁横公路岩溶塌陷区路基处理的措施与对策[J];地质与勘探;2001年03期
3 朱小恩;陈爱东;;一起桩基质量事故的处理[J];工程质量;2006年04期
4 冯雅妮;;复杂岩溶地区桩基施工技术[J];国防交通工程与技术;2011年06期
5 蒙晓红,方崇,罗捷;桩基础选型的模糊优化方法[J];广西大学学报(自然科学版);2005年03期
6 吴堂林,杨俊池;广和大桥主桥基础溶洞处理[J];华东公路;2002年03期
7 刘启蛟;王颖川;;海上大直径钻孔灌注桩施工探讨[J];山东交通科技;2010年02期
8 常洪德;;某工程钻孔灌注桩事故分析处理[J];山西建筑;2006年24期
9 项川;袁勇;胡艳军;;铁路路基岩溶病害的探测与处理[J];路基工程;2012年06期
10 钱斌;张格飞;;岩溶地区桩基础选型的实例分析[J];土工基础;2010年01期
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