| 摘要: |
| 为探究海洋平台桩基注浆加固承载性能, 针对黄河粉土开展24组直剪试验, 定量分析了水泥掺入比、固结压力对水泥土抗剪强度的影响规律。结果表明: 试样抗剪强度随着水泥掺入比的增加不断增大, 15%水泥掺入比试样的抗剪强度比原始粉土提高140%~209%; 25%水泥掺入比试样抗剪强度比原始粉土提高160%~246%。且水泥土强度参数(黏聚力、摩擦角)与水泥掺入比呈线性增长关系。当水泥掺入比相同时, 随着固结压力的增加, 水泥颗粒与土颗粒之间咬合更加密实, 试样的抗剪强度增加, 固结压力提高150 kPa时, 黏聚力提高了6%~12.5%, 摩擦角提高了9.6%~14.3%。埕岛油田海洋平台桩基注浆加固前后承载力数值计算结果表明, 桩基极限承载力由未注浆时的2 967 kN提高到注浆后5 379 kN, 增长了81.29%, 说明注浆技术能够有效地提升桩基承载能力。 |
| 关键词: 粉土 桩基 水泥掺入比 固结压力 直剪试验 |
| DOI：10.11759/hykx20240421001 |
| 分类号:P751 |
| 基金项目:国家自然科学基金项目(52078483) |
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| Experimental study on the shear strength of cemented soil by grouting in offshore platform pile foundations |
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CHEN Tongyan1, WU Min2, FENG Chunjian1, YANG Baoshan2, WANG Teng3, CUI Yongqiang3
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1.Sinopec Petroleum Engineering Corporation, Dongying 257206, China;2.Sinopec Shengli Oilfield Branch Offshore Oil Production Plant, Dongying 257237, China;3.School of Petroleum Engineering, China University of Petroleum (East China), Qingdao 266580, China
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| Abstract: |
| To investigate the bearing capacity enhancement of offshore platform piles through cemented reinforcement, with a focus on cemented silt. A systematic experimental program involving 24 direct shear tests were carried out to quantify the coupled effects of cement content and consolidation pressure on shear strength evolution. The results showed that the shear strength of the specimens increased continuously with the cement content. The shear strength of the sample with a 15% cement content was increased by 140%-209% compared to uncemented silt, and that of the sample with a 25% cement content was increased by 160%-246%. The strength parameters of cemented soil (cohesion and friction angle) displayed a linearly increasing relationship with the cement content. At the same cement content, higher consolidation pressures improved particle interlocking between cement and soil, leading to increased shear strength. When the consolidation pressure was increased by 150 kPa under the same cement content, the cohesion increased by 6%-12.5% and the friction angle by 9.6%-14.3%. Numerical calculations for the bearing capacity of pile foundations at Chengdao Oilfield offshore platforms revealed that the ultimate bearing capacity increased from 2 967 kN (uncemented) to 5 379 kN (cemented), marking an 81.29% improvement. This demonstrates the significant efficacy of grouting technology in enhancing pile foundation performance. |
| Key words: silt pile cement content consolidation pressure direct shear test |
