【摘要】：隨著石油／天然氣的開發(fā)走向深海,海上油氣開采平臺面臨日益惡劣的工作環(huán)境。采油平臺的失事會造成巨大的經濟損失和嚴重的人員傷亡。錨固系統(tǒng)作為深海油氣開采平臺的重要組成部分,對保證平臺安全運行具有關鍵作用。越來越深的開發(fā)水域對錨固系統(tǒng)提出了新的要求,錨固系統(tǒng)也逐漸由傳統(tǒng)的重力式基礎結構發(fā)展到由錨和錨鏈構成的懸鏈線系統(tǒng)。由于安裝簡便且安全可靠,板形重力安裝錨和吸力式安裝平板錨在海洋工程中得到了廣泛應用。但是對于這兩種板形錨(錨板)在深海黏土中應用時的性能,還沒有得到充分的認識。錨安裝完成時的姿態(tài)與最終承力時的姿態(tài)是不同的,錨要經過一個旋轉調節(jié)過程來達到最終承力姿態(tài)。這個調節(jié)過程將導致錨埋深的損失,從而降低錨的承載能力,而抗拔承載力是錨板設計的要點,也是海洋工程研究領域的熱點和基礎問題。因此,對錨板旋轉調節(jié)過程及其承載力特性的研究具有重要的理論意義和應用價值。本文以板形重力安裝錨(Gravity Installed Plate Anchor-GIPLA)和吸力式安裝平板錨(Suction Embedded Plate Anchor-SEPLA)為對象,采用塑性分析方法對黏土中錨的旋轉調節(jié)過程和承載力特性問題進行了研究。研究結果與三維大變形有限元(Three-dimensional Large Deformation Finite Element-3D-LDFE)分析方法的結果進行對比。并用塑性分析方法研究了上拔傾角和錨眼偏移角對埋深和承載力的影響、以及兩個參數(shù)的耦合作用,并由此找到了提高錨板承載力的應用條件和優(yōu)化設計方向。論文第一部分為板形重力安裝錨在黏土中的旋轉調節(jié)過程研究。由于板形重力安裝錨結構形式復雜,目前對板形重力安裝錨的研究都是基于實驗的。大多為貫入深度測試,其它的為拔出模型試驗。關于錨板在黏土中的承載力特性及旋轉調節(jié)過程的數(shù)值分析成果還未見到發(fā)表。為了探明板形重力安裝錨受到上拔力下潛的規(guī)律和內在機理,通過小變形有限元分析結合最小二乘擬合建立了塑性模型。用塑性分析方法對錨板的旋轉調節(jié)過程進行了研究,結果與大變形分析進行了比較,吻合很好。然后采用塑性分析方法研究了荷載傾角、錨眼偏移量以及土體強度特性等參數(shù)對承載力和埋深損失的影響規(guī)律。結果表明當加載角和錨眼偏移量設置恰當時,重力錨旋轉調節(jié)之后會下潛并提高抗拔承載力。論文第二部分研究了吸力式安裝平板錨在黏土中的旋轉調節(jié)過程。吸力式安裝平板錨有一個可繞錨爪旋轉的翼板。翼板的實際工作性能有很多學者進行過研究。但由于吸力式安裝平板錨幾何形狀復雜,這些研究對其均有較大程度的簡化,這些過多的簡化對研究結果可能會造成很大的誤差。本文充分考慮了吸力式安裝平板錨的實際結構型式和工作條件,對其在黏土中的旋轉調節(jié)過程進行了比較貼近實際的數(shù)值模擬,并對翼板的實際作用進行了分析。最后采用參數(shù)化方法研究了吸力式安裝平板錨的下潛潛能,并在此基礎上提出了對錨板進行優(yōu)化設計的方法。
[Abstract]:With the development of Petroleum / natural gas to the deep sea, the offshore oil and gas mining platform faces an increasingly harsh working environment. The failure of the oil production platform will cause huge economic losses and serious casualties. As an important part of the deep-sea oil and gas mining platform, the anchorage system plays a key role in the safe operation of the guarantee platform. Deep development waters have put forward new requirements for anchoring system. The anchorage system is gradually developed from the traditional gravity foundation to the catenary system composed of anchors and anchors. Because of the simple and safe installation, the plate gravity installation anchor and suction type installation plate anchor have been widely used in marine engineering. But for this two, it has been widely used in the marine engineering. The performance of the plate anchors (anchors) used in deep sea clay has not been fully understood. The posture of the anchorage is different from that of the final bearing, and the anchor must pass through a rotation adjustment process to achieve the final bearing attitude. This adjustment process will lead to the loss of the anchor depth, thus reducing the bearing capacity of the anchor. The thrust bearing capacity is the main point of the design of the anchor plate, and it is also a hot and basic problem in the field of marine engineering research. Therefore, it is of great theoretical significance and application value to study the rotation regulation process of the anchor plate and its bearing capacity characteristics. In this paper, the plate type gravity installation anchor (Gravity Installed Plate Anchor-GIPLA) and the suction type installation plate anchor (S Uction Embedded Plate Anchor-SEPLA) as an object, the plastic analysis method is used to study the rotation regulation and bearing capacity of the anchors in clay. The results are compared with the results of the three dimensional large deformation finite element analysis (Three-dimensional Large Deformation Finite Element-3D-LDFE) analysis method and the plastic analysis side is used. The influence of the uplift angle and the angle of the anchor eye offset on the buried depth and bearing capacity, and the coupling effect of the two parameters are studied, and the application conditions and the optimal design direction for improving the bearing capacity of the anchorage plate are found. The first part of the paper is the study on the rotary joint process of the plate shaped gravity installation anchor in the clay. It is complicated in form. At present, the research of plate gravity installation anchor is based on experiments. Most of them are penetration depth tests and other models are drawn out. The numerical analysis of the bearing capacity characteristics of the anchor plate in clay and the numerical analysis of the rotation regulation process have not yet been published. The plastic model is established by the finite element analysis of small deformation combined with the least square fitting. The rotational adjustment process of the anchor plate is studied by the plastic analysis method. The results are compared with the large deformation analysis. The plastic analysis method is used to study the load angle, the offset of the anchor eye and the strength of the soil. The effect of characteristics and other parameters on the bearing capacity and depth loss. The results show that when the loading angle and the anchor eye offset are set at the time, the gravity anchor rotation adjustment will descend and improve the uplift bearing capacity. The second part of the paper studies the rotation and joint process of the suction type plate anchorage in the clay. The actual working performance of the wing plates rotated around the anchorage has been studied by many scholars. But because of the complex geometry of the suction type plate anchors, these studies have greatly simplified them. These too many simplifications may cause great errors in the research results. The structure type and working condition are compared with the actual numerical simulation of the rotation regulation process in clay, and the actual function of the wing plate is analyzed. Finally, the potential of the suction type plate anchorage is studied by using the parameterization method. On this basis, a method for optimizing the design of the anchor plate is put forward.
【學位授予單位】：大連理工大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：P751

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相關期刊論文 前1條

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本文編號：2154945