偏心系数和锚腚角对固定锚腚拖曳锚嵌入运动影响的透明土试验研究

发布时间：2018-03-02 11:06

本文关键词： 固定锚腚拖曳锚偏心系数锚腚角运动轨迹模型试验　出处：《河北科技大学》2016年硕士论文　论文类型：学位论文

【摘要】：本文深海浮式结构必须在海底设置承受拉力的锚泊基础,固定锚腚拖曳锚因其具有重量轻、操作方便、成本低、可重复利用等优点被广泛应用。离心机实验和模型试验是研究拖曳锚在土中运动的主要方法。由于土体不透明,一些试验通常剖开土体观测板锚的运动及位置,另一些试验使用传感器测量,但效果不佳。因此,如何能直接观测板锚在土中的运动,是板锚在土中运动规律研究的关键。本文在国家自然科学基金项目“饱和-非饱和围岩峰后力学特性研究”(Nos.51274079)、“低渗煤层注入液氮致裂机理研究”(Nos.51574139)和河北省自然科学基金项目“海洋深水锚的土力学机理研究”(Nos.E2015208089)的资助下,自制了基于透明土的板锚拖曳试验装置,利用该装置研究了偏心系数和锚腚角对固定锚腚拖曳锚嵌入运动的影响规律,为拖曳锚的试验研究提供了新的思路。本文的主要研究内容包括:(1)制备了熔融石英砂透明土和水溶珠透明土;(2)自制了由玻璃水槽、板锚拖曳系统、图像采集及后处理系统、水溶珠透明土组成的板锚拖曳试验装置;(3)利用自制试验装置进行拖曳锚嵌入试验,研究了偏心系数和锚腚角对固定锚腚拖曳锚运动特性的影响;(4)运用Neubecker模型预测了本文模型锚的拖曳轨迹。通过本文研究主要获得如下结论:1)本文试验装置可直接观测板锚拖曳过程中的运动轨迹,这为板锚在土中运动规律研究提供了一种方法。2)锚眼法向偏心距和切向偏心距不是独立系数,偏心系数能综合描述锚眼偏心对板锚在土中运动的影响。3)锚腚角是影响板锚在土中运动的重要参数,随着锚腚角增加,板锚最终嵌土深度先增加后减小,对于饱和软粘土,锚腚角为50°~60°时,嵌土深度最大。4)随着锚眼偏心系数增加,板锚最终嵌土深度先增加后减小,偏心系数0.3时,嵌土深度最大。5)Neubecker模型基本能较好预测板锚在土中的运动规律。
[Abstract]:In this paper, the deep sea floating structure must be provided with the anchor foundation to bear the pull force on the bottom of the sea. The anchor is fixed and towed because of its light weight, convenient operation and low cost. The advantages of reusability are widely used. Centrifuge experiments and model tests are the main methods to study the movement of towed anchors in the soil. Because of the opacity of the soil, some tests usually dissect the motion and position of the anchor of the soil observation plate. Other experiments use sensors to measure them, but the results are not good. So how can we directly observe the movement of plate anchors in the soil, It is the key to study the motion law of slab and anchor in soil. In the project of National Natural Science Foundation of China, "study on post-peak mechanical properties of saturated-unsaturated surrounding rock" (Nos.512740799), "study on mechanism of injecting liquid nitrogen into low permeability coal seam" (Nos.51574139) and natural science of Hebei Province. Funded by the fund project, "study on the soil Mechanics Mechanism of Marine Deep Water Anchors", funded by "Nos.E2015208089", The self-made plate anchor towing test device based on transparent soil is used to study the influence of eccentricity coefficient and anchor angle on the embedded motion of fixed anchor drag anchor. The main research contents of this paper include the preparation of fused quartz sand transparent soil and water-soluble bead transparent soil, and the self-made glass flume, plate anchor towing system, image acquisition and post-processing system. Water soluble bead transparent soil composed of plate anchor towing test apparatus, using self-made test equipment to carry out towing anchor embedding test, The influence of eccentricity coefficient and angle of anchor on the motion characteristics of fixed anchor drag anchor is studied. (4) Neubecker model is used to predict the towing trajectory of the anchor in this paper. The main conclusions are as follows: 1) the test device in this paper can directly predict the drag trajectory of the model anchor. The track of motion in the course of the anchor towing of the observation plate, This provides a method for studying the motion of plate anchors in soil. 2) normal eccentricity and tangential eccentricity are not independent coefficients. Eccentricity coefficient can describe the influence of eccentricity of anchor eye on the movement of plate anchor in soil. 3) the angle of anchor bottom is an important parameter that affects the motion of plate anchor in soil. With the increase of anchor angle, the depth of embedded soil increases first and then decreases, for saturated soft clay, When the angle of anchoring is 50 掳or 60 掳, the maximum depth of soil embedded. 4) with the increase of eccentric coefficient of anchor eye, the ultimate depth of embedded soil increases first and then decreases. When the eccentricity coefficient is 0.3, the maximum depth of embedded soil. 5. Neubecker model can basically predict the movement law of plate anchor in soil.
【学位授予单位】：河北科技大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：P75

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