本文選題：低裙式吸力樁 + 超低位真空預(yù)壓法�。� 參考：《天津城建大學(xué)》2017年碩士論文

【摘要】：為了提高裙式吸力樁的承載力,本文在考慮“土塞”效應(yīng)的基礎(chǔ)上,提出了一種新型低裙式吸力樁模型,使其更易于沉貫且能更好地保護(hù)主桶周圍土體免受洋流刨蝕。為了驗(yàn)證新型低裙式吸力樁模型的合理性,分別制作了傳統(tǒng)單桶式吸力樁模型、普通裙式吸力樁模型與本文提出的新型低裙式吸力樁模型做對比試驗(yàn)。為了模擬海洋土體,本文提出了一種快速固結(jié)土體的方法——超低位真空預(yù)壓法。該方法能夠快速固結(jié)土體,明顯縮短固結(jié)時(shí)間。采用該方法加固的土體,能夠較好地模擬海洋地基土,其強(qiáng)度沿深度方向增加。通過SEM圖像及滲透性分析,得出該土體的物性指標(biāo)及滲流穩(wěn)定性良好。然后采用抽真空的方式在水下沉貫各類模型樁,并采用雙桶負(fù)壓法沉貫裙式吸力樁模型,驗(yàn)證低裙式吸力樁模型的可行性。試驗(yàn)結(jié)果表明雙桶負(fù)壓法能有效減小“土塞”高度,對試驗(yàn)所得數(shù)據(jù)進(jìn)行擬合,得出了更加適用于本試驗(yàn)條件的沉貫阻力公式。隨后,結(jié)合實(shí)際工程中吸力樁受力工況,采用本文提出的立面內(nèi)多角度拉拔試驗(yàn)裝置對吸力樁模型進(jìn)行45°斜拉拔試驗(yàn),為了相互驗(yàn)證吸力樁的承載力,又采用PLAXIS 3D有限元分析軟件對拉拔試驗(yàn)進(jìn)行模擬,證明了低裙式吸力樁的合理性。最終得到以下主要結(jié)論:(1)采用抽真空法沉貫吸力樁,“土塞”現(xiàn)象不可避免;(2)低裙式吸力樁模型的可貫性優(yōu)于普通裙式吸力樁模型;(3)本文提出的新型低裙式吸力樁模型可有效減小“土塞”高度;(4)擬合出的吸力樁模型沉貫阻力適用于強(qiáng)度沿深度方向增加的土體,更接近于實(shí)際工程;(5)新型低裙式吸力樁模型45°抗拔承載能力優(yōu)于傳統(tǒng)單桶式吸力樁及普通裙式吸力樁模型;(6)本文模擬得到的吸力樁抗拔承載力——樁體斜位移曲線與室內(nèi)模型試驗(yàn)結(jié)果吻合度較高,相互驗(yàn)證了試驗(yàn)及數(shù)值模擬的合理性。
[Abstract]:In order to improve the bearing capacity of skirt suction pile, a new model of low skirt suction pile is proposed on the basis of considering the "soil plug" effect, which makes it easier to sink and can better protect the soil around the main bucket from ocean current planing. In order to verify the rationality of the new low skirt suction pile model, the traditional single bucket suction pile model, the ordinary skirt suction pile model and the new low skirt suction pile model proposed in this paper are compared with each other. In order to simulate the marine soil, a method of rapid consolidation of soil is presented in this paper, which is the ultra-low vacuum preloading method. This method can rapidly consolidate the soil and shorten the consolidation time. The strength of the soil reinforced by this method can be simulated well and its strength increases along the depth. Through SEM image and permeability analysis, the physical property index and seepage stability of the soil are obtained. Then the vacuum method is used to sink all kinds of model piles under water, and the double bucket negative pressure sinking skirt suction pile model is used to verify the feasibility of the low skirt suction pile model. The test results show that the double-barrel negative pressure method can effectively reduce the height of the "soil plug". The experimental data are fitted and the sinking resistance formula is obtained, which is more suitable for this test condition. Then, combined with the load condition of suction pile in the actual engineering, the suction pile model was tested with the multi-angle drawing test device proposed in this paper in order to verify the bearing capacity of the suction pile. The drawing test was simulated by PLAXIS 3D finite element analysis software, and the rationality of low skirt suction pile was proved. The main conclusions are as follows: (1) the suction pile is sunk by vacuum pumping method. The phenomenon of "soil plug" is inevitable; (2) the penetration of low skirt suction pile model is better than that of ordinary skirt suction pile model; (3) the new low skirt suction pile model proposed in this paper can effectively reduce the height of "soil plug"; (4) the fitted suction pile model can be obtained. Type I penetration resistance is applicable to soils whose strength increases in the direction of depth. (5) the 45 擄uplift bearing capacity of the new type of low skirt suction pile model is better than that of the traditional single bucket suction pile and the ordinary skirt suction pile model. (6) the uplift bearing capacity of the suction pile obtained in this paper is the inclined displacement curve of the pile body. The results of the line and the indoor model test are in good agreement with each other. The rationality of the test and numerical simulation is verified by each other.
【學(xué)位授予單位】：天津城建大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：TU473.1

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 李大勇;翟漢波;張雨坤;;裙式吸力基礎(chǔ)在層狀土中沉貫的滲流數(shù)值分析[J];海洋技術(shù)學(xué)報(bào);2014年06期

2 李大勇;馮凌云;張雨坤;郭彥雪;;飽和細(xì)砂中裙式吸力基礎(chǔ)水平單調(diào)加載模型試驗(yàn)——承載力及變形分析[J];巖土工程學(xué)報(bào);2013年11期

3 李大勇;馮凌云;郭彥雪;曹立雪;;裙式吸力基礎(chǔ)水平承載數(shù)值分析[J];巖土工程學(xué)報(bào);2013年S1期

4 李大勇;張雨坤;高玉峰;宋言江;;中粗砂中吸力錨的負(fù)壓沉貫?zāi)Ｐ驮囼?yàn)研究[J];巖土工程學(xué)報(bào);2012年12期

5 姚濤;余建星;李志剛;周美珍;周全智;;筒型基礎(chǔ)貫入過程中的滲流分析[J];海岸工程;2012年01期

6 李大勇;劉小麗;孫宗軍;;海上風(fēng)電塔架基礎(chǔ)的新型吸力錨研發(fā)[J];海洋技術(shù);2011年03期

7 朱斌;孔德瓊;童建國;孔令剛;陳仁朋;;粉土中吸力式桶形基礎(chǔ)沉貫及抗拔特性試驗(yàn)研究[J];巖土工程學(xué)報(bào);2011年07期

8 李大勇;王梅;劉小麗;;離岸裙式吸力基礎(chǔ)在砂土地基中沉貫性研究[J];海洋工程;2011年01期

9 倪云林;辛華龍;劉勇;;我國海上風(fēng)電的發(fā)展與技術(shù)現(xiàn)狀分析[J];能源工程;2009年04期

10 劉俊濱;李玉峰;劉金鐸;;吸力錨沉放過程中土塞形成的有限元分析[J];水科學(xué)與工程技術(shù);2007年03期

相關(guān)會議論文 前1條

1 李大勇;劉小麗;;裙式吸力錨負(fù)壓沉貫滲流場特性分析[A];第十五屆中國海洋（岸）工程學(xué)術(shù)討論會論文集(中)[C];2011年

相關(guān)博士學(xué)位論文 前1條

1 李馳;軟土地基桶形基礎(chǔ)循環(huán)承載力研究[D];天津大學(xué);2006年

，

本文編號：2095143