防波堤椭圆形桶式基础结构的贯入受力特性实验研究

发布时间：2018-05-26 22:31

本文选题：桶式基础防波堤 + 下沉阻力　；参考：《海洋工程》2014年01期

【摘要】：某工程拟在深水软土地基上修筑防波堤,为了尽量减少地基处理充分利用天然地基,创新性设计出一种轻型薄壁的预制防波堤结构,其挡浪部分为直立薄壁圆筒,基础部分则为倒扣的薄壁椭圆形桶,并且椭圆形下桶为外壁和内隔板分成9个格室,防波堤结构浮运至指定位置后,拟采用负压工法施工安装就位。这种新型防波堤结构为国内外首次提出,其下沉施工设计尚无规范可循,为此开展了土工离心模型试验,在模型加速过程中模拟了椭圆形下桶基础在淤泥层中的自重下沉,之后利用新研发了一种大行程作动加载装置给椭圆形下桶施加下推力,让其继续向下贯入直至穿越整个淤泥层,以模拟负压工法的贯入下沉。试验测量了下桶贯入下沉过程中的推力与贯入位移,还尝试测量了桶壁和内隔板断面的压应变,由此分析了下桶基础的下沉总阻力、桶壁摩擦力以及截面压应变随贯入位移的变化。结果发现,这些曲线均出现了转折点,根据转折点对应的下沉总阻力确定了椭圆形下桶基础贯入过程所遭遇的临界下沉总阻力值,据此估算了负压工法中所需施加的压力差。
[Abstract]:A certain project plans to build breakwater on deep water soft soil foundation. In order to minimize the treatment of foundation and make full use of natural foundation, a light thin-walled precast breakwater structure is designed innovatively. The wave-retaining part of the breakwater is an upright thin-walled cylinder. The foundation part is an inverted thin-walled oval barrel, and the bottom oval barrel is divided into nine latticed chambers with outer wall and inner partition. After the breakwater structure is floating to a specified position, the construction and installation of the breakwater is to be carried out with negative pressure method. This new breakwater structure is first put forward at home and abroad, and the design of sinking construction has not been followed. Therefore, geotechnical centrifuge model test is carried out. In the process of model acceleration, the gravity subsidence of oval bottom bucket foundation in silt layer is simulated. Then a large stroke actuation loading device is developed to push the lower oval bucket into the bottom of the elliptical bucket, which can continue through the whole silt layer to simulate the penetration and subsidence of the negative pressure engineering method. The thrust and penetration displacement during the sinking of the lower barrel are measured, and the compressive strain of the bucket wall and the cross section of the inner partition are also tried to be measured, and the total sinking resistance of the bottom bucket foundation is analyzed. The variation of barrel wall friction force and cross section compressive strain with penetration displacement. The results show that there are turning points in these curves. According to the total sinking resistance corresponding to the turning point, the critical total sinking resistance of the elliptical bottom bucket foundation is determined, and the pressure difference required in the negative pressure method is estimated.
【作者单位】：南京水利科学研究院水文水资源与水利工程国家重点实验室;南京土壤仪器厂有限公司;
【基金】：国家高技术研究发展计划(863计划)资助项目(2012AA112510)
【分类号】：U656.2

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