英语翻译Forms should be designed by conventional engineering pra

英语翻译
Forms should be designed by conventional engineering practices to resist the forces resulting from the known loads.If designed by experience or guesswork ,the forms might be too light and subject to an expensive failure.On the other hand,the forms could be stronger than necessary and cost too much.
When forms are to be used many times,that part of the form in contact with the concrete must be of a good grade of material,which will have a high first cost but will be economical due to more than one use.If the finish surface of the concrete must be smooth and free of blemishes,the use of a very high grade of material will minimize expensive finishing.
To attain maximum economy in formwork ,the highest practical unit stresses for the form material should be used.When the concrete is just cast,it is more or less fluid and exerts considerable side pressure on the forms.In several hours time after the concrete has set up,the side pressure will cease and the beam with its reinforcement will carry its own dead plus the superimposed live loads; and stresses in the formwork will be practically nothing.Thus the forms will be subjected to maximum stresses for a very short period of time.Wood is capable of absorbing large overloads if the stresses are on short duration,and because of this the allowable stresses based on constant loads of long duration may be increased by,say one third ,as long as the forms ,which are to be reused,are protected from abuse and excessive exposure to weather.However,it must be noted that the allowable deflections in formwork will many times govern the design for the reason that if the weight of the fresh concrete deflects the membrer too much,either horizontally or vertically,the finished concrete will set up in the deflected shape.
Some ways by which the cost of formwork may be kept at a minimum are the following:
1.Have the structural and architectural designers prepare their plans at the same time so that they may both be compatible with an economical system of formwork.
2.Keep the structural system uncomplicated so that the formwork may be simple and economically erected erected and removed.
3.Use the same size of columns over a whole building,if possible ,or at least over several floors.This will permit the reuse of beam and column forms without alteration.
4.Space the columns uniformly ,if possible ,or if not ,retain the same pattern floor to floor.
5.Space columns,if possible ,to fit the use of plywood sheets for decking without cutting.
6.Use the same width for column and column-supported girders to eliminate the cutting and fitting of girder forms into column forms.
7.Specify beams of the same size and depth for each floor,and choose the depth that will permit the use of standard lumber sizes for beam sides.
Of course ,it will not be feasible to let the attempt to achieve maximum formwork economy completely override all other considerations; however,any economies within

表格应设计工程的实践,通过传统的抗压力产生的负载.如果所设计的经验或臆测,形式可能太轻,服从一个昂贵的失败.另一方面,我们不可能比认有必要时,得花费过多.
当形式是使用多次,这部分的形式在与混凝土一定的优质材料,具有很高的费用,但将经济由于多个使用.如果完成混凝土表面光滑、免费必须有瑕疵,使用一种非常高品位的资料将会减少昂贵的完成.
来获得最大的经济在模板,最高的实际单位应力对形态的材料应该被使用.当混凝土,它只产生或多或少的流体压力相当大的一面.在几小时后混凝土已不再,侧压力下和以其加固将自己的死加上叠合活荷载应力、模板将微不足道.这样的形式将受到最大压力为一个很短的一段时间.木头能吸收大量的压力正在超负荷持续时间短、因为这容许应力的基础上长时间持续不断增加,可说的三分之一,只要形式,它是被重用,防止滥用和过度暴露的天气.
然而,必须指出,在允许的变形模板将多次管辖,理由是如果新拌混凝土质量的membrer偏转太多,水平或垂直,完成的具体将设在外形设计偏转.
其中的一些成本的模板可在保持最低限度的方法如下：
1.具有结构和建筑设计师准备自己的计划,同时使他们都是兼容的经济体系的模板.
2.保持简单的结构体系的模板可以使经济和简单的安装和移除.竖起
3.使用相同大小的整个建筑,如果可能的话,或者至少在几层楼.这将允许重用的梁、柱形态没有改变.
4.这个专栏空间统一,如果可能的话,或者,如果不是这样,保持相同的图案地板层.
5.空间的栏目,如果可能,适合使用胶合板床单等装饰无切削.
6使用的列和列相同的宽度,支梁,以消除切割到列形式的梁形式的拟合.
7.指定梁的大小和深度,并选择每层深度,将允许使用标准的木材尺寸为梁两侧.
当然,它将不会是可行的,让企图实现最大的模板生态