| 分层土中裙式吸力基础吸力沉贯特性模型试验研究 |
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| 引用本文： | 张雨坤,秦廷辉,李大勇,王冲冲.分层土中裙式吸力基础吸力沉贯特性模型试验研究[J].岩土力学,2022,43(5):1317-1325. |
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| 作者姓名： | 张雨坤 秦廷辉 李大勇 王冲冲 |
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| 作者单位： | 1. 山东科技大学 山东科技大学土木工程防灾减灾重点实验室，山东 青岛 266590；
2. 中国石油大学 储运与建筑工程学院，山东 青岛 266580 |
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| 基金项目： | 国家自然科学基金项目（No.51808325,No.51879044,No.51639002）；;山东省自然科学基金（No.ZR2019BEE007）~~； |
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| 摘 要： | 针对一种新型海上风电基础形式-裙式吸力基础，开展模型试验，研究其在分层土地基中的沉贯特性。讨论了土层分布形式（砂土、黏性土、上层砂土及下层黏性土（简称上砂下黏）、上层黏性土及下层砂土（简称上黏下砂））、沉贯方式的影响。研究表明：裙式吸力基础在分层土中具有良好的沉贯性能。与传统吸力基础相比，裙式吸力基础在砂土、黏性土、上砂下黏和上黏下砂地基中最终沉贯深度较传统吸力基础分别增加10.0%、2.3%、3.0%和9.6%，沉贯最大吸力值分别增加0.9%、14.4%、66.2%和92.2%。黏性土层位置和厚度对基础沉贯特性影响显著。上黏下砂地层中，基础最大吸力值出现在土层分界面处，最大吸力值随土层分布系数t（上层土厚度与土体总厚度的比值）的增加而逐渐增大，最终沉贯深度随土层分布系数增加而逐渐减小。上砂下黏地层中，裙式吸力基础最大吸力值出现在最大沉贯深度处，吸力最大值随土层分布系数的增加而逐渐减小，最终沉贯深度受土层分布系数影响较小。此外，同时抽吸主桶和裙结构内水体进行沉贯，最终沉贯深度大于只抽主桶情况。在砂土、黏性土、上黏下砂（ 0.4）和上砂下黏（ 0.4）等4种地基中，裙式吸力基础采用同时抽主桶和裙结构的沉贯方式，最终沉贯深度较只抽主桶情况分别增大了13.8%、3.4%、16.4%和4.6%。研究成果为进一步阐明吸力基础在分层土中沉贯机制及指导工程实践，具有借鉴意义。
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| 关 键 词： | 裙式吸力基础（MSC） 分层土 模型试验 沉贯方式 吸力变化 土塞高度 |
| 收稿时间： | 2021-08-09 |
| 修稿时间： | 2021-12-23 |
Model tests on installation behavior of modified suction caissons in layered soil |
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| ZHANG Yu-kun,QIN Ting-hui,LI Da-yong,WANG Chong-chong.Model tests on installation behavior of modified suction caissons in layered soil[J].Rock and Soil Mechanics,2022,43(5):1317-1325. |
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| Authors: | ZHANG Yu-kun QIN Ting-hui LI Da-yong WANG Chong-chong |
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| Institution: | 1. Key Laboratory of Civil Engineering Disaster Prevention and Mitigation, Shandong University of Science and Technology, Qingdao,
Shandong 266590, China; 2. College of Pipeline and Civil Engineering, China University of Petroleum, Qingdao, Shandong 266580, China |
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| Abstract: | Model tests were conducted to investigate the installation behavior of modified suction caisson (MSC) and regular suction caisson (RSC) in layered soil (sand, clay, sand over clay and clay over sand). It was found that the MSC can penetrate the layered soil to the desired depth. The final penetration depths for MSC in sand, clay, sand over clay and clay over sand increase approximately 10.0%, 2.3%, 3.0% and 9.6%, compared with the RSC. In addition, the maximum required suctions for MSC in sand, clay, sand over clay and clay over sand increase approximately 0.9%, 14.4%, 66.2% and 92.2%, compared with the RSC. It was found that the installation behavior of MSC in layered soil is strongly influenced by the position and the thickness of the clay layer. When the MSC penetrates clay over sand, the maximum value of suction is achieved when the suction caisson tip contacts the interface between sand and clay. The maximum applied suction increases with increasing the soil distribution coefficient t (ratio of upper soil thickness to the total soil thickness). However, the final penetration depth was found to decrease with increasing the t value. When the MSC penetrates sand over clay, the maximum applied suction was obtained at the final penetration depth. The maximum applied suction decreases with increasing the t value. The soil distribution coefficient has little effect on the final penetration depth for MSC in sand over clay. In addition, the installation way effectively influences the final penetration depth. The final penetration depths for MSC in sand, clay, clay over sand ( 0.4) and sand over clay ( 0.4) under the installation way of simultaneously pumping out water in the internal compartment and external structure increase about 13.8%, 3.4%, 16.4% and 4.6%, compared with those under the installation way of only pumping out water in the internal compartment. This study results can guide the design and construction of the suction caisson in layered soil. |
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| Keywords: | modified suction caisson (MSC) layered soil model test installation way suction variations soil plug height |
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