土层

The roots of spring-sown maize and summer-sown maize could touch with each other in relay-planting system, which made the roots competed for water and nutrition. Thus, more of the water and nitrogen in those soil layers were used, which led to the decrease of water and nitrogen in those soil layers.

玉米根系数量和TTC还原总量在剖面分布上均发生交叉，春、夏玉米间存在养分与水分的竞争，使根系所达到的区域土壤养分和水分利用量增加，从而使相应土层土壤全氮含量和水分含量下降。

So, this thesisresearches soil cement's engineering property in Beijing area through the largenumbers of tests.

为此，本文通过大量的室内试验对北京地区土层搅拌后的水泥土工程性能进行了研究。

In studies of interaction among pile, platform that above it and surrounding soil, this paper employ the concept of plate element to simulate the loading character of platform, and employ the concept of solid element to simulate the character of pile and soil, using the finite element method after understanding the geometry properties of pile, soil and the platform. Analyzing the loading properties of the three entities above and their deformation, this paper also employ a special element, Penalty Element. The introduction of penalty element of this kind has served to guarantee the join harmony of displacement between solid element and plate element, thereby effectively resolving the join problem between platforms, pile that support it and surrounding soil.Considering significant property difference between pile material and its surrounding soil, there may be much shear stress on their contact interface produced under vertical load, thus causing displacement or fission. Therefore it is necessary to adopt one special constitutive law of this kind of contact interface, which can reflect its feature of loading and deformation thoroughly. On the basis of the deformation feature and constitutive laws of some contact interface obtained by Zhang Dongji and people concerned through some single-shear experiments on contact interface between structure and soil, this paper employ one pile-soil three-dimensional constant thickness contact interface model to simulate the " slide" taken place on the interface between pile and its surrounding soil. With this kind model, this paper has also created one finite element model, which can be applied to perform finite element calculation and analyze the pile-loading feature, and deduced its element stiffness matrix.

在承台-桩-土共同作用中，考虑桩与承台的几何特性，采用有限元方法，用实体单元模拟桩土，用板单元模拟承台，更具体地分析桩和承台的受力特性和变形，而且还采用罚单元—既实体单元与板单元之间连接必须满足变形协调条件，来有效地解决了承台与桩土的连接问题，且在桩土共同作用中，由于桩体结构的材料性能与周围土层性质相差较大，在竖向荷载下有可能在其接触面上产生较大的剪应力从而导致错动或开裂，因此，为了充分反映桩土接触面上的受力及变形特征，应采用一种桩土接触面特有的本构关系，即利用张冬霁等人关于结构与土体接触面单剪试验所得到的接触面变形特征及其本构关系，引入桩-土三维等厚度接触单元来模拟桩与桩侧土之间的&滑移&，在此基础上建立可用于桩基承载性状分析的有限元计算单元模型，并推导出了各单元的刚度矩阵。

So the vertical vibration of rigid foundation embedded in a single-layered poroelastic soil based on rigid bedrock is then studied by using the same approximate method.The vertical dynamic impedance and dynamic response factor for different values of soil layer thickness are discussed.

因此文中采用Novak简化计算模型接着研究了下卧基岩单层饱和地基中埋置刚性基础的竖向振动，分析了不同土层厚度下基础的竖向动力刚度、动力放大系数曲线。

Usually, maximum shear modulus is determined by strain method in laboratory, rather than by shear velocity method in-situ,and based on it,shear modulus ratio and damping ratio of soil can be provided.

最大剪切模量是影响土的动剪切模量比、阻尼比和土层地震反应的最重要参数之一。

They serve as a separation layer to form a stable boundary between layers of soil to maintain the integrity, character and performance properties of each layer.

土工织物相当于一个隔离层，在不同的土层之间形成稳定边界，以保持每层的完整性、固有特性以及使用性能。

For a natural soil layer, before building, in general, the displacement due to self-weight has been finished.

一般情况下，建筑物建造前天然土层在自重作用下的变形早已结束。

The process of sand absorption is:(1) the vibration head vibrates and losses the sand layer, and supply high pressure air into the sand absorption head;(2) the high pressure air generates negative pressure in the sand absorption pipe when it is discharged out from the sand absorption;(3) the sand absorption head and the vibration are shifted downwards and maintains the water flow straightly.

取砂土的过程为：(1)振动头振动松散砂土层，同时向吸砂头供入高压空气；(2)高压空气通过吸砂头从排砂管向上排出的过程中，在吸砂管内产生负压，吸砂管将管口处的水和砂土吸入到吸砂头内，在高压气流作用下，吸砂头内的砂、水和气混合而成的三相流通过排砂管排出到受砂船上；(3)在吸砂的过程中，适时地将吸砂头和振动头下移并保持钻孔套管中的水流畅通。

The device includes a drill spigot inserting into the marebase sand layer through the upper cover soil layer, there sets air inlet, sand discharging pipe and vibration connecting pipe in the drill spigot; there sets a sand absorption head on the bottom of the air inlet and sand discharging pipe; the bottom of the vibration connecting pipe connects with the vibration head; the sand absorption head is made up of a centre cavity, ring cavity and sand absorption pipe.

该装置包括一穿透上部覆盖土层插入到海底深埋砂土层的钻孔套管，在钻孔套管内，设有进气管、排砂管和振动连接管；进气管和排砂管的下端连接一个吸砂头；振动连接管的下端连接振动头；吸砂头由一中心腔室、环状腔体和吸砂管构成。

Based on field conditions and soil characteristics, a new kind of horizontal drainage material is adopted, which is composed of flexible permeable pile and thin sand layer.

根据场地条件和土层特性，采用软式透水管与薄层砂垫层组成的新型水平排水体，并进行精心设计和施工。

I didn't watch TV last night, because it .

昨晚我没有看电视，因为电视机坏了。

Since this year, in a lot of villages of Beijing, TV of elevator liquid crystal was removed.

今年以来，在北京的很多小区里，电梯液晶电视被撤了下来。