下底板

To give the definition of the mass concrete and to concrete\'s cracks together with practical meanings of control ,and give a brief review on the research in the field at home and abroad, at last, methods to control temperature crack of the mass concrete from several aspects such as design measures,concrets material, construction schedules.etc are summed up; To explain the physical mechanics of the concrete and computing methods-Difference Method and Finite Element Method, and illustrate the application of their specific methods repectively;Several temperature factors that can influence the temperature stress of mass concrete baseplate are analyzed. The influence degree of temperature factor can be got through the ANSYS simulation computation the control of temperature can control the temperature stress, consequently control the temperature crack of mass concert baseplate; through the influence of the crack resistance ability of mass concrete baseplate which takes the reinforcement as a part is analyzed. By ANSYS simulation, the best suited volume ratio of reinforcement is found out, at same time the layout of reinforcement with the same volume ratio can also affect the resistance ability of mass concrete baseplate. Sum up of above analysis, anti-crack function of steel bar in early mass concrete baseplate is obvious, so it\'s necessary to consider beneficial effect of construction steel bar in research of temperature control on mass concrete baseplate.

本文先容了大体积混凝土及混凝土裂缝的基本概念，对国内外在这个领域里的研究现状作了扼要叙述，并从结构设计、混凝土材质、施工措施等方面总结了大体积混凝土温度裂缝控制的方法及防止措施；阐述了混凝土的基本物理力学性能，总结了大体积混凝土温度计算的方法——差分法和有限元法，并分别举例说明其具体应用的方法；分析了影响大体积混凝土底板温度应力的几种温度因素，利用ANSYS模拟计算，得出了每种因素的影响程度，通过分析提出了在这几种温度影响因素下如何通过控制温度以达到控制温度应力从而来控制裂缝的具体建议；针对大体积混凝土基础底板中配筋的不同对混凝土底板抗裂能力的影响不同，利用ANSYS进行模拟分析，得出底板中最合适的体积配筋率，同时分析了在相同体积配筋率下钢筋的具体布置对大体积混凝土基础底板抗裂能力的影响，分析表明，配置钢筋对混凝土结构的开裂阻止作用明显，在研究大体积混凝土温度裂缝题目时，要考虑钢筋在其中的有利作用。

The floor of the vessel has a cavity (3) therein extending downwardly from the surface of the floor, and the lower end of the liquid reagent level sensor (2) and temperature sensor (1 and 11) are positioned in the cavity.

该器皿的底板具有设在其中并从底板的表面向下延伸的凹穴(3)，并且液体反应物液位传感器(2)和温度传感器(1，11)的下端位于该凹穴内。

In working, the tube via tube hoop is connected to the upper bottom plate (2); the lower bottom plate (3) is fixed to the groundsill; when the tube is vibrated, the distortion of spring can damp and adsorb the three-dimensional vibration of tube. The invention has lower natural frequency and wider temperature application, with simple structure and easy maintenance.

工作时，需减振的管道通过管箍与本发明所述的三维减振器的上底板(2)固接，三维减振器的下底板(3)与地基固接，当管道产生振动时，通过弹簧的变形来减小和吸收管道的三维振动，达到减振的目的，它具有较低的固有频率和较大的使用温度范围，具有结构简单可靠、安装方便、维护简便的优点。

The paper is based on the theory of inter-function between water and rock, and losing energy in rock mass, brought forward that the water flow has head loss during water flow intruding through the coal seam effective water-resisting layer and energy waste concept for splitting rock mass, and analyzed the form of the remaining water pressure. Through the simulation experiment in the preventing water capability of water-resisting rocks in the coal seam scaleboard, studied the law, character of the losing in water head waste and the relation to pressure, water-resisting of hydrogeology and engineering geology character. Brought forward the new method of calculating the water inrush coefficient.

通过理论分析和实验研究，本文得出以下结论：高承压水在沿煤层底板隔水层导升过程中存在着明显的压力水头损失；同一地层条件下，煤层底板承压水水头压力越大其导升过程中的水头压力损耗就越大；同一水头压力条件下，地层的渗透性越差其阻水能力越强，水流导升过程中的水头压力损耗也越大；在同一介质中，当初始水头压力不同时，水流在导升过程中水头压力的衰减不同，在同一隔水介质中底板含水层水头压力越大其沿隔水层导升过程中的水头损耗也就越大，水头损耗随底板隔水层水头压力增加而呈递增趋势，另外它们相应的水头衰减速率也呈递增趋势，煤层底板隔

Those rarely refer to the researches about water pressure function mechanism. In fact, the water flow intrudes upwards with a loss of the distance water and energy wastes for splitting rocks when confined groundwater intrudes upwards through coal seam water-resisting layer. The water flow under the coal seam scaleboard consumes more energy after it intrudes at a certain height.

实际上，煤层底板高承压含水层水沿隔水底板岩层向上导升过程中，存在一定的沿程水头损失和劈裂岩体裂隙的能量损耗，下伏含水层高压水在底板隔水层下部劈裂导升一定的高度后，在导升段的能量消耗很大，这时作用于有效隔水层段下部的实际水压已远远小于含水层中的观测水压，真正作用在有效隔水层上的水压为残余水压P_c，对底板有效隔水层起破坏作用的有效水压力亦应为残余水压。

Like dinghies, these boats have floors you don't have to remove when stowing the boat.

类似前一种橡皮艇，这种艇在运输时也不需要拆下底板。

In order to analyze the influence and damage of the top and bottom of rock mass in floor water-resisting layers due to water pressure in water bearing layer and mining pressure, this paper applies the methods of similar material simulation test and mechanical analysis of floor water invasion in the near of faultage to further comprehend the mechanism of floor water invasion.

为了分析底板含水层水压及采动矿压对底板隔水层岩体上部与下部的影响与破坏，应用了相似材料模拟试验以及断层附近底板突水的力学分析方法，对底板突水机理有了进一步的认识；同时，由断层附近底板突水的力学分析方法所得到的理论计算结果，也可以作为判别类似条件下遇断层时承压水体上采煤是否安全的依据。

In this paper,the stability of arch slab under the action of the plunging jet is investigated.The pressures on upper and lower surfaces of the slab and push force of arch abutment are measured.A generalized formula for uplift force is proposed.

通过实验分析，研究了冲击射流下拱形底板失稳型式，量测了底板上、下表面压强分布，概化了时均上举力的计算公式，实测了动水荷载作用下拱端推力。

At the same time, the relationship between the magnetic flux leakage signals and the physical characters (including the width、depth and position) of the corrosions are studied. The results identify that, if the floor is saturated, the magnetic flux leakage intensity changes linearly with the changing of the corrosion diameter. When the corrosion is in the surface, the peak value of the signal is higher than it's in the back.

同时对缺陷直径、深度以及处于底板上不同位置所产生的漏磁场信号差异进行研究，结果表明，在磁化饱和条件下，平底孔缺陷漏磁场信号峰峰值与孔深度呈线性关系，相同大小的缺陷处于底板下表面时检测信号强度大于处于底板上表面时。

The procedure is applied in two projects:(1) Shanghai Huanqiu finance center tower foundation pit dewatering, the complicated flow state of groundwater is simulated under these conditions which the aquifers deposite layer by layer, the bottom of the aquifers goes deep to 149m, the horizontal flow barrier goes deep to 34m, the extraction wells are penetrated to 55m, the filters of the extraction wells are located between 34m to 55m, and the water level in the deep foundation pit is decreased to 26m under land surface, the result of 8 pumping wells optimization project is designed.(2) The forth subway of Dong Jia-du tunnel repair foundation pit dewatering in Shanghai, the complicated flow state of groundwater is simulated under these conditions which the aquifers deposite layer by layer, the bottom of the aquifers goes deep to 144.45m, the horizontal flow barrier goes deep to 65m, the extraction wells are penetrated to 60m, the filters of the extraction wells are located between 45m to 60m, and the water level in the deep foundation pit is decreased to 42.45m under land surface, then an optimization project is designed.

最后将成果分别应用于两个工程实例中：(1)上海环球金融中心塔楼基坑降水，模拟了在多层含水层复合存在、含水层最深底板埋深达149m、基坑周围挡水连续墙埋深达34m、抽水井埋深达55m、抽水井过滤器埋深为34至55m，基坑内地下水位降至埋深达26m的情况下的地下水复杂流动状态，得出了8口抽水井优化降水方案；(2)上海地铁4号线董家渡隧道修复基坑降水，模拟了在多层含水层复合存在、含水层最深底板埋深达144.45m、基坑周围挡水连续墙埋深达65m、抽水井埋深达60m、抽水井过滤器埋深为45至60m，基坑内地下水位降至埋深达42.45m的情况下的地下水复杂流动状态，确定出了最优降水方案。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。