蒙河大桥岩溶地质桥梁桩基施工处理技术
发布时间：2019-04-16 08:59
【摘要】：蒙河大桥在地理位置上处于蒙河之上,蒙河的河床深度在4-8米之间,河床中主要的物质成分：中砂,蒙河河床的中砂层下面还包括0.4 m到1.2m厚沉积性可区分的粉质粘土,粘土土层下面大面积遍布着材质坚硬的石炭纪石灰岩。需要特别注意的是,中度和强度程度风化的石灰岩大致的厚度程度在1 m的水平,风化的石灰岩的下面属于微风化程度的石灰岩。由于地质运动阶段河水和地下水之间的相互作用,与此同时发生了一系列的反应,发生了潜蚀反应,同时在重力的作用下,逐步出现了溶洞,溶洞迅速发育变大,且溶洞内大多存在填充物质,多为可塑性粉质性粘土,易于和水发生反应。研究主要针对桥梁建筑过程中的桩基施工部分,通过明确岩溶地区勘探方法、桩基承载力模拟计算确定设计阶段的处理方案,从设计初期尽可能的避开溶洞分布密集的区域。之后针对本桥进行设计方案的比选,确定施工预处理方案及事故处理预案。在桥梁建设开始之前,重新对每根桩位都进行详细的地理钻探,形成详细的勘探资料。对于发现的溶洞探明其内部是否存在填充物,并取样研究。填充物取样后对其进行土工试验,分析岩溶地区的填充物的物理力学特征,测试填充物的容重、测试填充物的含水量、测试填充物的孔隙率等,为下一步进行溶洞处理提供相关的参数依据。依据地质钻探提供的相关详细的资料以及各种各样的填充物实际的情况,在施工前针对存在溶洞的桩基制定预处理方案及专项施工方案。针对溶洞易出现事故的施工过程制定出详细的处理预案,针对施工中出现的事故,参照施工经验并结合现场实际,选择合适的处理方案,及时处理了事故,经后期桩基质量检测,符合设计及规范的要求。通过上述研究主要得出如下结论：在临沂地区岩溶地质普遍发育较好的区域,综合考虑现阶段的施工能力、机械设备和技术水平,采用注浆预处理和回填造壁法相结合的施工方法是比较适宜的,这种方案增加成本较低,仅在钻探及出现溶洞的应急处理过程中增加部分施工费,相比其他施工方案,较为经济实用,且对工期影响较小,性价比较高。
[Abstract]:The Menghe Bridge lies geographically above the Menghe River. The bed depth of the Menghe River is between 4m and 8m. The main material component in the riverbed is medium sand. The middle sand layer of the Menghe River bed also consists of silty clay with thickness of 0.4 m to 1.2 m, which is covered with hard Carboniferous limestone in a large area under the clay soil layer. Special attention should be paid to the fact that moderately and intensively weathered limestone is roughly 1 m thick and below the weathered limestone belongs to slightly weathered limestone. As a result of the interaction between river water and groundwater during the geological movement, at the same time, a series of reactions and latent corrosion took place. At the same time, under the action of gravity, the cave gradually appeared, and the cave developed rapidly. Most of the caves are filled with plastic silty clay, which is easy to react with water. The research mainly aimed at the pile foundation construction part in the bridge building process, through the clear karst area exploration method, the pile foundation bearing capacity simulation calculation determines the design stage treatment plan, from the design initial stage as far as possible avoids the karst cave distribution dense area. After that, the design scheme of this bridge is compared and selected, and the pre-treatment scheme and accident treatment plan are determined. Before the construction of the bridge begins, every pile is re-drilled in detail to form detailed exploration data. Find out if there are fillers in the cave, and sample it. After sampling the fillers, the geotechnical tests are carried out to analyze the physical and mechanical characteristics of the fillers in karst areas, to test the bulk density of the fillers, to test the moisture content of the fillers, and to test the porosity of the fillers, etc. Provide the relevant parameter basis for the next step of the cave treatment. According to the detailed data provided by geological drilling and the actual situation of various fillers, the pre-treatment scheme and special construction plan for pile foundation with karst cave are made before construction. In view of the accident-prone construction process of karst cave, a detailed treatment plan is made. According to the accident in construction, referring to the construction experience and combining with the actual situation on the spot, the appropriate treatment scheme is selected and the accident is dealt with in time. After testing the quality of pile foundation in the later period, it meets the requirements of design and code. The main conclusions are drawn as follows: in the area where karst geology is generally well developed in Linyi area, the construction capacity, mechanical equipment and technical level of the present stage are considered comprehensively. The construction method combining grouting pretreatment with backfill wall building method is more suitable. This scheme increases the cost of construction and only increases part of the construction cost in the process of drilling and emergency treatment of karst cave, compared with other construction schemes. More economical and practical, and less impact on the time limit, the price of performance is relatively high.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U445.551
本文编号：2458653
[Abstract]:The Menghe Bridge lies geographically above the Menghe River. The bed depth of the Menghe River is between 4m and 8m. The main material component in the riverbed is medium sand. The middle sand layer of the Menghe River bed also consists of silty clay with thickness of 0.4 m to 1.2 m, which is covered with hard Carboniferous limestone in a large area under the clay soil layer. Special attention should be paid to the fact that moderately and intensively weathered limestone is roughly 1 m thick and below the weathered limestone belongs to slightly weathered limestone. As a result of the interaction between river water and groundwater during the geological movement, at the same time, a series of reactions and latent corrosion took place. At the same time, under the action of gravity, the cave gradually appeared, and the cave developed rapidly. Most of the caves are filled with plastic silty clay, which is easy to react with water. The research mainly aimed at the pile foundation construction part in the bridge building process, through the clear karst area exploration method, the pile foundation bearing capacity simulation calculation determines the design stage treatment plan, from the design initial stage as far as possible avoids the karst cave distribution dense area. After that, the design scheme of this bridge is compared and selected, and the pre-treatment scheme and accident treatment plan are determined. Before the construction of the bridge begins, every pile is re-drilled in detail to form detailed exploration data. Find out if there are fillers in the cave, and sample it. After sampling the fillers, the geotechnical tests are carried out to analyze the physical and mechanical characteristics of the fillers in karst areas, to test the bulk density of the fillers, to test the moisture content of the fillers, and to test the porosity of the fillers, etc. Provide the relevant parameter basis for the next step of the cave treatment. According to the detailed data provided by geological drilling and the actual situation of various fillers, the pre-treatment scheme and special construction plan for pile foundation with karst cave are made before construction. In view of the accident-prone construction process of karst cave, a detailed treatment plan is made. According to the accident in construction, referring to the construction experience and combining with the actual situation on the spot, the appropriate treatment scheme is selected and the accident is dealt with in time. After testing the quality of pile foundation in the later period, it meets the requirements of design and code. The main conclusions are drawn as follows: in the area where karst geology is generally well developed in Linyi area, the construction capacity, mechanical equipment and technical level of the present stage are considered comprehensively. The construction method combining grouting pretreatment with backfill wall building method is more suitable. This scheme increases the cost of construction and only increases part of the construction cost in the process of drilling and emergency treatment of karst cave, compared with other construction schemes. More economical and practical, and less impact on the time limit, the price of performance is relatively high.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U445.551
【参考文献】
相关期刊论文 前1条
1 李志荣,王振宇;岩溶地区钻孔灌注桩的设计与施工[J];工程建设与设计;2000年01期
相关硕士学位论文 前1条
1 刘小松;岩溶地区基础与地基的设计研究[D];天津大学;2004年
，本文编号：2458653
本文链接：https://www.wllwen.com/kejilunwen/daoluqiaoliang/2458653.html
