In any case ,pile tips should not have a diameter less than 150 mm.Timber piles can not withstand hard driving stress;therefore,the pile capacity is generally limited to about 220-270KN.Steel shoes may be used to avoid damage at the pile tip.The tops of timber piles may also be damaged during the driving operation.The crushing of the wooden fibers caused by the impact of the hammer is referred to as brooming.To avoid damage to the pile top,a metal band or a cap may be used.
Spilcing of timber piles should be avoided, particularly when they are expected to carry tensile load or lateral load. However, if splicing is necessary,it can be done by using either pipe sleeves or metal straps and bolts. The length of the pipe sleeve should be at least five times the diameter of the pile. The butting ends should be cut square so that full contact can be maintained. The spliced portions should be carefully trimmed so that they fit tightly to the inside of the pipe sleeve. In the case of metal straps and bolts, the butting ends should also be cut square. Also, the sides of the spliced portion should be trimmed plane for putting the straps on.
參考答案:[以下仅供参考，希望有所帮助]
不管怎样，桩帽直径不得小于150毫米。木桩无法承受打桩带来的强大压力；因此桩的受力范围只能局限在大约220-270KN。可使用钢鞋避以免桩帽受损。木桩的顶端也可能会在打桩的过程中受到损坏。因捶击而导致的木质纤维被称作“扫除”。为避免桩顶受损，可使用金属镶边或者金属盖帽。
应尽量避免木桩的插接，特别是当木桩需承载相当的张力荷载或侧面负荷时。但是，一旦需要使用插接，应当使用护管或金属绑扎和螺栓。护管的长度至少应为5倍于木桩的直径。接头处应该修理成四方形，以利于保障充分的接触面积。插接的部分应该做好饰边工作，从而可以与护管的内部紧凑的衔接。如果用到金属绑扎或者螺栓，接头处则也应修理成四方形。插接部分的边缘可以进行刨平处理，以利于进行绑扎。
