| 摘要: |
| 针对实际工程应用中水泥土搅拌桩出现的桩身强度分布不均匀、成桩质量差等问题，对传统的边钻进边搅拌施工工艺进行改进。改进的水泥土桩采用钻孔外预先搅拌均匀水泥土浆液，再边钻孔边浇筑的施工工艺，从而形成了一种性质可调控的新型环保均质塑性桩体（Environmental Homogeneous Plastic Pile）—EHP工法桩。通过对现场取芯样和室内方法制备水泥土试样开展一系列的无侧限抗压试验，并结合桩体芯样剖面物质组成分析，对EHP工法桩的强度特性进行了研究。建立了不同形状水泥土试样强度间的定量关系，通过引入强度折减系数对改进施工工艺现场制备桩体强度的折减幅度进行了分析。结果表明，改进施工工艺制备的水泥土桩桩身均匀性和桩体强度均优于传统施工工艺制备的水泥土桩，且有效地基加固深度明显增大。和室内标准养护试样相比，不同施工工艺制备的水泥土桩，均出现一定程度的强度折减。对于EHP工法桩，桩体强度折减系数随水泥掺量的增加而减小，在（0.55, 0.75）范围内变化。和传统施工工艺制备的水泥土桩相比，EHP工法桩的强度降低幅度相对较小，具有更优良的承载能力。 |
| 关键词: 水泥土桩 施工工艺 无侧限抗压强度 桩身均匀性 桩身强度折减 |
| DOI： |
| 分类号:TU43 |
| 基金项目:国家自然科学基金项目（面上项目，重点项目，重大项目） |
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| Experimental study on the strength behavior of EHP |
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duxuqing1, wengjiaxing2, biexueqing2, songmiaomiao3, qiuchengchun3, lihui4
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1.Huaihe Committee Huaihe Project Construction Administration Bureau;2.Jiangsu Hongji Water Source Technology Co., Ltd;3.Yancheng Institute of Technology Department of Civil Engineering;4.Jiangsu Province Engineering Investigation and Research Institute Co., Ltd
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| Abstract: |
| An improved soil-cement mixing pile construction method was developed to solve the issues such as uneven distribution of pile strength and poor pile quality appeared in the traditional mixing while drilling method. Based on the new method, an Environmental-friendly and Homogeneous Plastic (EHP) pile was formed following the procedure that cement-soil slurry mixture was blended outside the drilling hole before being mixing while drilling, which enable the operation was controllable and adjustable. In this study, a series of unconfined compression tests were conducted on cement-soil samples prepared in the laboratory and field to evaluate the strength characteristics of EHP piles with various cement contents. The quantitative relationships between the unconfined compressive strength and different shapes were established. The strength reduction coefficient was employed to analyze the reduction in the unconfined compressive strength for in-situ EHP piles. Results indicate that the uniformity and strength of EHP plies are better than those constructed using the traditional construction technology. The improved construction technology can reinforce soft ground within greater depth. Compared with the samples made in laboratory and cured under standard conditions, a reduction in unconfined compressive strength of cement-soil mixing pile was found. The reduction coefficient RP of strength was introduced to evaluate the reduction in strength of EHP piles. Results showed that the value of RP decreases with the increasing cement content and RP is in the range of (0.55, 0.75). Compared with the pile constructed using traditional method, the reduction in unconfined compressive strength for EHP pile is relatively small indicating a better bearing capacity. |
| Key words: soil-cement pile construction technology unconfined compressive strength pile uniformity reduction in pile strength |
