Immersed tunnel foundation on marine clay improved by sand compaction piles     

Hongtao He  Yougao Lin  Jianyu Li  Nan Zhang 《Marine Georesources & Geotechnology》2018,36(2):218-226

The sand compaction pile (SCP) method can be applied to soft marine clay ground that is a reinforcement of composite ground consisting of compacted sand piles and surrounding clay. The application of SCP method in the immersed tunnel of Hong Kong–Zhuhai–Macao Bridge verify SCP method is a robust solution to limit the total settlement and differential longitudinal settlement and to promote smooth transition from immersed tunnel to artificial island. The SCP method has significant settlement reduction effect on marine clay. The SCPs can also function as a drainage path to accelerate the consolidation process in marine clay. It is also found that the consolidation rate of SCP-improved ground is delayed compared with that predicted program which is most probably because of the soil disturbance effect during the installation of SCPs.  相似文献   

Estimation of survival probability for a ship in beam seas using the safe basin   总被引：1，自引：0，他引：1  

Zhan-Jun Long  Joon-Young Kim 《Ocean Engineering》2010,37(4):418-424

The purpose of this paper is to analyze the nonlinear ship roll motion equation and the main parameters that induce ship capsizing in beam seas, estimate the survival probability of a ferry in random seas and to find out a risk assessment method for the ship’s intact stability. A single degree of freedom (1-DOF) dynamic system of ship rolling in beam seas is investigated and the nonlinear differential equation is solved in the time domain by the fourth order Runge-Kutta algorithm. The survival probability of a ferry in beam seas is investigated using the theory of “safe basin”. The survival probability is calculated by estimating erosion of “safe basin” during ship rolling motion by Monte Carlo simulations. From the results it can be concluded that the survival probability of a ship in beam sea condition can be predicted by combining Monte Carlo simulations and the theory of “safe basin”.  相似文献   

爆破挤淤法围堰施工质量控制及安全防范     

贾延权  甘细木  郭守东  王艳红 《海岸工程》2010,29(2):49-55

针对爆破挤淤法围堰施工炸药用量大、破坏力强、工程施工质量控制难且存在较大安全隐患的特点,介绍了连云港市海滨新区围堰施工质量控制方法及安全管理经验,以供类似环境下围堰或其他爆破挤淤工程施工参考。  相似文献   

碾压混凝土结构的接缝灌浆技术     

张发明  陈俊 《地球科学与环境学报》1999,21(2):2

在碾压混凝土结构中进行接缝灌浆,是目前坝工研究的重要技术问题。以某工程为例,详细分析了影响接缝灌浆质量的因素,提出了特殊条件下接缝灌浆的技术方法  相似文献   

The influence of anisotropy on compaction bands: The case of coaxiality between stress and fabric anisotropy tensors     

Chara Prassa  Sotiris Alevizos  Manolis Veveakis  Yannis F. Dafalias 《国际地质力学数值与分析法杂志》2022,46(1):68-88

Compaction bands are localized failure patterns that appear in highly porous rock material under the effect of relatively high confining pressure. Being affected mainly by volumetric compression, these bands appear to be almost perpendicular to the most compressive principal stress of a stress state at the so-called “cap” of the yield surface (YS). In this study, we focus on the mechanism that leads to the onset of compaction bands by using a viscoplasticity model able to describe the post-localization response of these materials. The proposed constitutive framework is based on the overstress theory of Perzyna (1966) and the anisotropic clay plasticity model of Dafalias (1986), which provides not only the necessary “cap” of the YS, but introduces a rotational hardening (RH) mechanism, thus, accounting for the effect of fabric anisotropy. Following the analysis of Veveakis and Regenauer-Lieb (2015), we identify the compaction bands as “static” cnoidal wave formations in the medium that occur at a post-yield regime, and we study the effect of rotational and isotropic hardening on their onset. Moreover, we determine a theoretical range of confining pressures in triaxial compression tests for the compaction bands to develop. Under the assumption of coaxiality between stress and anisotropy tensors, the results show that the isotropic hardening promotes compaction localization, whereas the RH has a slightly negative effect on the onset of compaction localization.  相似文献   

Meso-mechanism of rolling dynamic compaction to reinforce loose landslide dam materialEI北大核心     

李文炜  占鑫杰  王保田  朱群峰  许小龙  左晋宇  王家辉 《岩土力学》2023,(8):2297-2307

为系统研究冲击碾压过程中松散堰塞坝料的细观密实机制,基于自行设计的可视化冲击碾压模型装置及粒子图像测速技术,研究了不同冲击碾压参数对堰塞坝料地基的表面变形、内部变形及颗粒位移规律的影响。试验结果表明,冲击碾压加固过程是冲击和碾压两者共同作用,由于水平冲击作用,冲击点下方地基的变形具有非对称性。“高速轻轮”的施工参数会强化冲击效果,弱化碾压效果,造成地基表面平整性差。堰塞坝料冲击轮加固过程中的最大位移发生在三边形冲击轮圆弧面较平滑处与土体接触时,随后由于模型冲击轮重心上升,地基出现部分弹性回弹。提高冲击轮的牵引速度能够促进冲击能量向深层传递,但水平影响宽度有限;提高冲击轮的质量则能促进能量向两侧水平方向传递,但影响深度有限。对于模型试验的易贡堰塞坝料地基,冲击碾压最佳牵引速度约为0.75 m/s。结果可为堰塞坝料地基的冲击碾压浅层加固提供理论依据。  相似文献   

压实度对脱硫石膏动强度和动孔压影响试验          下载免费PDF全文

谭彩  万里  袁明道  卢博  杨文滨 《地震工程学报》2021,43(5):1238-1243

为研究压实度对脱硫石膏动强度与动孔压特性影响，对压实度为0.85、0.90和0.95三组脱硫石膏进行等压固结不排水振动三轴试验，试验围压为100 kPa、200 kPa和400 kPa。结果表明：随压实度增大，脱硫石膏颗粒间作用力愈强，颗粒联结骨架越不容易破坏，脱硫石膏动强度越大，动孔压增长越慢；试验压实度范围下，脱硫石膏动剪应力比和动内摩擦角均与压实度呈线性相关；试验用脱硫石膏可分类定名为低液限粉土，其动强度曲线和动孔压发展模式均与常规粉土类似，分别可通过幂函数和对数函数表征，经F值试验法检验，其统计回归显著性水平均为"高度显著"。  相似文献