本文選題：海積軟土　切入點(diǎn)：動(dòng)力特性　出處：《廣西大學(xué)》2017年碩士論文

【摘要】：吹填場(chǎng)地往往下伏著大面積、深厚的沉積相軟土,在發(fā)生地震時(shí)有很大可能會(huì)對(duì)地震波產(chǎn)生放大作用,繼而會(huì)加劇吹填場(chǎng)地上部建筑的損害,因此對(duì)吹填場(chǎng)地海積軟土的動(dòng)力響應(yīng)研究極為必要。含水量、固結(jié)度及圍壓作為影響海積軟土動(dòng)力與強(qiáng)度特性的因素,分析以上因素對(duì)海積軟土動(dòng)力特性的具體影響是本文主要探討的問(wèn)題。本文通過(guò)GDS動(dòng)三軸儀對(duì)防城港企沙工業(yè)園區(qū)吹填場(chǎng)地下伏海積軟土進(jìn)行了大量的動(dòng)力測(cè)試。研究了不同含水量、固結(jié)度與圍壓對(duì)海積軟土動(dòng)力與強(qiáng)度特性的影響,試圖為吹填場(chǎng)地抗震設(shè)計(jì)及防震減震提供經(jīng)驗(yàn)及數(shù)據(jù)支持。主要的研究?jī)?nèi)容包括海積軟土基本物理力學(xué)參數(shù)的試驗(yàn)、不同因素作用下海積軟土動(dòng)變形試驗(yàn)、不同因素作用下的動(dòng)強(qiáng)度試驗(yàn)。本文通過(guò)以上的工作內(nèi)容得出的結(jié)論如下。1.不同的動(dòng)應(yīng)力幅值下的動(dòng)應(yīng)變呈現(xiàn)了不同的規(guī)律,隨著動(dòng)應(yīng)力幅值的增大動(dòng)應(yīng)變從平穩(wěn)狀態(tài)往擴(kuò)張狀態(tài)過(guò)渡;圍壓、含水量、固結(jié)度對(duì)于海積軟土的滯回曲線與骨干曲線的發(fā)展、動(dòng)彈性模量與阻尼比的大小有極大影響。根據(jù)現(xiàn)有的試驗(yàn)數(shù)據(jù),利用Hardin-Drnevich雙曲線模型對(duì)各骨干曲線進(jìn)行了擬合,計(jì)算出各試驗(yàn)條件下的最大阻尼比與最大動(dòng)彈模,并建立了動(dòng)彈性模量衰減模型。2.確定了以10%的軸向應(yīng)變作為試樣破壞標(biāo)準(zhǔn)。圍壓與含水量對(duì)于海積軟土動(dòng)強(qiáng)度有較大影響,隨著圍壓增大動(dòng)強(qiáng)度越大,而含水量越大動(dòng)強(qiáng)度越小。計(jì)算出了不同含水量與破壞振次的動(dòng)強(qiáng)度指標(biāo)cd、φd,結(jié)果表明動(dòng)強(qiáng)度指標(biāo)cd、φd會(huì)隨著含水量與破壞振次的增大而減小。
[Abstract]:Filling sites are often covered with large areas of deep sedimentary soft soil, which is likely to magnify seismic waves in the event of an earthquake, which in turn will aggravate damage to the upper building of the filling site.Therefore, it is necessary to study the dynamic response of marine soft soil on the filling site.Water content, consolidation degree and confining pressure are the factors that affect the dynamic and strength characteristics of marine soft soil, and it is mainly discussed in this paper to analyze the specific influence of the above factors on the dynamic characteristics of marine soft soil.In this paper, a large number of dynamic tests have been carried out on the underground voluminous soft soil of the blowing yard in Jisha Industrial Park of Fangchenggang by using the GDS dynamic triaxial instrument.The effects of different water content, consolidation degree and confining pressure on the dynamic and strength characteristics of marine soft soil are studied in this paper.The main research contents include the test of the basic physical and mechanical parameters of the marine soft soil, the dynamic deformation test of the marine soft soil under different factors, and the dynamic strength test under the different factors.The conclusions of this paper are as follows. 1.With the increase of the amplitude of dynamic stress, the dynamic strain changes from stationary state to expanding state, confining pressure, water content,The degree of consolidation has great influence on the development of hysteretic curve and backbone curve of marine soft soil and the magnitude of dynamic elastic modulus and damping ratio.According to the existing test data, the Hardin-Drnevich hyperbolic model was used to fit the backbone curves, the maximum damping ratio and the maximum dynamic elastic modulus were calculated under each test condition, and the dynamic modulus attenuation model was established.The axial strain of 10% is used as the failure criterion.Confining pressure and water content have great influence on the dynamic strength of marine soft soil. With the increase of confining pressure, the dynamic strength is larger, but the larger the water content is, the smaller the dynamic strength is.The dynamic strength indexes cdand 蠁 d of different water content and failure times are calculated. The results show that the dynamic strength index cdand 蠁 d decrease with the increase of water content and failure times.
【學(xué)位授予單位】：廣西大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：U652.2

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 周文權(quán);冷伍明;劉文R，

本文編號(hào)：1712999