长江三角洲晚更新世末期古土壤与古环境   总被引：4，自引：0，他引：4  

刘宝柱  李从先  业治铮 《中国海洋大学学报(自然科学版)》1997,(3)

长江三角洲地区第一暗绿色硬粘土层是上海地区主要建筑持力层之一，也是划分全新统与更新统的标志层，前人已做过大量研究，但尚缺乏古土壤方面的系统研究工作。本文首次从古土壤学的角度系统研究了该层的古土壤特征，通过粒度分析发现有粘粒的生成，微形态研究发现有粘粒及铁锰、碳酸盐等化学组分的迁移与淀积，化学全量分析得出该层的硅铝率为２．８０～３．３７，说明该层已发生较强的成土作用，可以确认该层为古土壤层，并进一步把该层划分为４个Ｂ层、３个Ａ层，亦即该层为复合古土壤层。根据该层的成土特征，将其命名为古潮土  相似文献   

烟单14号玉米产量与土壤养分关系的研究     

李淑霞  冯瑞龙  赵继业  刘绍棣  程绍义 《中国海洋大学学报(自然科学版)》1988,(Z2)

根据大量田间试验和调查资料分析,作者提出烟单14号玉米生长过程中,小喇叭口期土壤中全氮、大喇叭口期土壤中速效磷的含量与产量相关密切。并据此建立了产量及构成三因素与土壤养分间的最优相关模型。  相似文献   

A Note on Soil Structure Resistance of Natural Marine Deposits   总被引：1，自引：1，他引：1  

洪振舜刘松玉  刘志方 《中国海洋工程》2004,18(2):321-326

It has been well documented that natural normally-consolidated marine soils are generally subjected to the effects of soil structure. The interpretation of the resistance of soil structure is an important issue in the theory study and engineering practice of ocean engineering and geotechnical engineering. It is traditionally considered that the resistance of soil structure gradually disappears with increasing stress level when the applied stress is beyond the consolidation yield stress. In this study, however, it is found that this traditional interpretation of the resistance of soil structure can not explain the strength behavior of natural marine deposits with a normally-consolidated stress history A new interpretation of the resistance of soil structure is proposed based on the strength behavior. In the preyield state, the undrained strength of natural marine deposits is composed of two components: one developed by the applied stress and the other developed by the resistance of soil structure. When the applied stress is beyond the consolidation yield stress, the strength behavior is independent of the resistance of soil structure.  相似文献   

港口靠船桩工作性状计算的双参数法   总被引：8，自引：0，他引：8  

谢耀峰 《海洋工程》2002,20(2):38-42,48

港口靠船桩是承受重复性荷载或多循环荷载的一种横向承载桩。双参数法能较好地描述靠船桩 (单桩、群桩 )的桩土工作性状。用双参数法进行计算时 ,所给的地面条件必须由重复荷载或多循环荷载作用下实测出来。根据现场试桩资料 ,标定桩土参数 ,即k =mx1/n的指数l/n、桩土相对柔度系数α、桩土综合刚度EI等值 ,可以用来设计试桩附近局部地区同类条件下的其它长桩。对于没有进行试桩的某些工程 ,可以联合运用双参数法和p -y曲线法进行桩的分析  相似文献   

孪井灌区主要作物节水灌溉模式的研究     

刘贯群  朱新军  王淑英  陈浩  韩曼 《中国海洋大学学报(自然科学版)》2006,36(5):809-816

根据内蒙古孪井滩灌区的自然地理、地质和水文地质条件,在室内外模拟试验的基础上,利用VS2DT模型对灌溉入渗水的运移进行了模拟,计算了现有灌溉量下的渗漏量,提出了灌区春小麦和夏玉米的节水灌溉模式。春小麦第一次灌溉的节水灌溉量为150 mm,第二次灌水的节水灌溉量为97.5 mm,以后4次灌水的灌溉量在60~75 mm之间。夏玉米第一次灌水的灌溉量也以150 mm为宜,以后5次灌溉量分别以127.5 mm,90.0 mm,97.5 mm,82.5 mm及67.5 mm为宜。此灌溉模式不仅能够节约水资源,而且能够防止土壤次生盐渍化的发展。  相似文献   

The Working Mechanism and An Analytic Method of the Deep Embedded Large Cylinder Structure     

孙克俐  周锡礽钱荣 《中国海洋工程》2004,18(2):221-228

The large cylinder is a new-type structure that has been applied to harbor and offshore engineering. An analytic method of the relationship between loads and the structure displacement is developed based on the failure mode of deep embedded large cylinder structures. It can be used to calculate directly the soil resistance and the ultirnate bearing capacity of the structure under usage. A new criterion of the large cylinder structure, which discriminates the deep embedded cylinder from the shallow embedded cylinder, is defined. Model tests prove that the proposed method is feasible for the analysis of deep embedded large cylinder structures.  相似文献   

一种具有巨大经济价值的海洋矿产资源--砂石土     

蔡秋蓉  陈俊仁  吴能友 《海洋地质前沿》2003,19(2):6-8,13

砂石土指第四纪堆积的泥、土、砂，为一种极为重要的资源。我国具有丰富的海洋砂石土资源。以广东海域为例，通过资料的综合分析，探讨了海岸砂石土资源的重要作用，并提出其开采应注意的问题。  相似文献   

氯化物型盐碱地池塘底泥中水溶性盐的分布特征     

张美昭  张兆琪  郑伟刚  董双林 《海洋湖沼通报》2001,(4):50-55

1997－1999年夏天，对位于黄河下游的氯化物型盐碱地池塘底泥中的水溶性盐进行了分析。结果表明：底泥中的含盐量，SO^2-4,Ca^2 ,Mg^2 含量是随着塘龄的增加而升高，而其余离子基本不随塘龄的增加而变化。各离子的垂直分布为“泥－土”混合层的含量较低，“水－泥”交界层含量较高。  相似文献   

Influence of large-diameter pipe pile driving on surrounding marine soils and adjacent submarine pipelines     

Jinzhong Dou  Zhong-Jie Zhang 《Marine Georesources & Geotechnology》2021,39(1):15-33

Abstract

With the large-scale development and utilization of ocean resources and space, it is inevitable to encounter existing submarine facilities in pile driving areas, which necessitates a safety assessment. In this article, by referring to a wharf renovation project as a reference, the surrounding soil response and buried pipe deformation during pile driving in a near-shore submarine environment are investigated by three-dimensional (3D) numerical models that consider the pore water effect. Numerical studies are carried out in two different series: one is a case of a single pile focusing on the effect of the minimum plane distance of the pile–pipe, and the other is a case of double piles focusing on the effect of the pile spacing.  相似文献   

山东全新世滨海软土与工程地质灾害的研究   总被引：2，自引：0，他引：2  

吴建政 《海洋地质与第四纪地质》1995,15(3):43-54

山东全新世滨海软土分布在海湾、泻湖、河口区，厚度１－１０ｍ。海湾、泻湖软土为淤泥、淤泥质土，陆源物质供应丰富的浅水区，软土颗粒偏粗，强度相对较高，触变性对建筑物危害性大，陆源物质供应少的深水区，软土颗粒偏细，低强度、高压缩性、沉降变形大和蠕变性是危及建筑物稳定的主要因素。海湾、泻湖软土位于地下水位下，具低透水性，掩埋后短期不易排水固结，软土下为强度较高的冲积物，对一般建筑物，利用强夯、粉喷搅拌桩、  相似文献