Dean-中英对照.doc

14. 梁和桁架14.1 配合比 包含轧制型材（有或无盖板），钢管截面或拼合截面的梁和桁架应该根据总截面或改良的总截面的性质进行配比。无需缩小腹板或翼缘中的紧固孔，除非这些紧固孔所引起的翼缘面积的缩小超过了总翼缘面积的15%。为紧固件打其他孔的影响请参照14.3.3。 No deduction need be made for fastener holes in webs or flanges unless the reduction of flange area by such holes exceeds 15% of the gross flange area, in which case the excess shall be deducted. The effect of openings other than holes for fasteners shall be considered in accordance with Clause 14.3.3节.14.2 翼缘14.2.1 焊接梁的翼缘应该包括单个钢板或一系列由完全焊透的坡口焊法端-端连接起来的钢板。14.2 Flanges 14.2.1 Flanges of welded girders should consist of a single plate or a series of plates joined end-to-end by complete penetration groove welds.14.2.2 栓接梁的翼缘应该均匀，这样的话盖板的总截面积才不至于超过总翼缘面积的70%。14.2.2 Flanges of bolted girders shall be proportioned so that the total cross-sectional area of cover plates does not exceed 70% of the total flange area.14.2.3紧固件或连接翼缘和腹板的焊缝应该均匀，以抵抗由于弯曲以及任何自翼缘传至腹板的负荷所引起的水平剪力，而不是直接承受。一般来说，紧固件或间断焊缝的间距应该与剪力的强度一致， 而且不能超过受压构件和受拉构件允许间距的最大值。请参照19节。14.2.3 Fasteners or welds connecting flanges to webs shall be proportioned to resist horizontal shear forces due to bending combined with any loads that are transmitted from the flange to the web other than by direct bearing. Spacing of fasteners or intermittent welds in general shall be in proportion to the intensity of the shear force and shall not exceed the maximum for compression or tension members as applicable, in accordance with Clause 19. 14.2.4部分长度的翼缘盖板应该超出理论切割点，而且超出的部分应该与足够多的紧固件或焊缝相连，以此于理论切割点在盖板中产生一个力，这个力不应小于其中=盖板中产生的力=盖板面积=理论切割点的设计极限荷载引起的力矩=从盖板的形心到盖板截面的中性轴的距离=盖板截面的惯性矩14.2.4 Partial-length flange cover plates shall be extended beyond the theoretical cut-off point, and the extended portion shall be connected with sufficient fasteners or welds to develop a force in the cover plate at the theoretical cut-off point not less than where = required force to be developed in cover plate = area of cover plate = moment due to factored loads at theoretical cut-off point = distance from centroid of cover plate to neutral axis of cover-plated section = moment of inertia of cover-plated section 此外，对于焊接的盖板，连接盖板端部和梁或者桁架的焊缝应该能够在长度a内产生力P。a应从盖板的实际末端量起。定义如下：(a) 在长度a中，当盖板末端和两个边缘有连续的等于或大于盖板厚度3/4的焊缝时，a =盖板宽度；(b) 在长度a中，当盖板末端和两个边缘有连续的小于盖板厚度3/4的焊缝时，a =1.5倍的盖板宽度；(c) 在长度a中，当盖板末端没有焊缝但两个边缘有连续的焊缝时，a =2倍的盖板宽度。Additionally, for welded cover plates, the welds connecting the cover-plate termination to the beam or girder shall be designed to develop the force, P, within a length, a, measured from the actual end of the cover plate, determined as follows: (a) a = width of the cover plate when there is a continuous weld equal to or larger than three-fourths of the cover-plate thickness across the end of the plate and along both edges in the length a; (b) a = 1.5 times the width of the cover plate when there is a continuous weld smaller than three-fourths of the cover-plate thickness across the end of the plate and along both edges in the length a; and (c) a = 2 times the width of the cover plate when there is no weld across the end of the plate but there are continuous welds along both edges in the length a. 14.3 腹板1.4.3.1 最大长细比腹板的长细比h/w不应大于83 000/其中=钢材的屈服点如果分析显示受压翼缘在腹板中的屈曲在达到设计极限荷载时不会发生，可以取消这个限制。14.3 Webs 14.3.1 Maximum Slenderness The slenderness ratio, h/w, of a web shall not exceed 83 000/ where = specified minimum yield point of the compression flange steel This limit may be waived if analysis indicates that buckling of the compression flange into the web will not occur at factored load levels.14.3.2 腹板压屈和屈服腹板的轴向抵抗力取值如下：（a）对于内力（自构件末端的距离大于构件深度的集中荷载），应取与之中数值较小的那一个。（b）对支座反力，应取与之中数值较小的那一个。其中，=支座长度任何时候只要超出了腹板的抵抗力，就必须使用支承加劲肋（参照14.4节）14.3.2 Web Crippling and Yielding The factored bearing resistance of the web shall be taken as follows: (a) for interior loads (concentrated load applied at a distance from the member end greater than the member depth), the smaller of (b) for end reactions, the smaller of Where N= length of bearingWherever the bearing resistance of the web is exceeded, bearing stiffeners shall be used (see Clause 14.4). 14.3.3 开孔14.3.3.1除了14.1节提到的之外，在设计过程中梁和桁架中的所有开孔都应该考虑到。如果在某一点剪力设计值和净截面的力矩超出了构件的承载力，就应该在这一点的构件上进行加固，以提供所需的强度和稳定性。14.3.3 Openings Except as provided in Clause 14.1, the effect of all openings in beams and girders shall be considered in the design. At all points where the factored shear or moments at the net section would exceed the capacity of the member, adequate reinforcement shall be added to the member at that point to provide the required strength and stability.14.3.3.2无筋圆孔可能位于未加强的1类和2类梁与桁架的腹板中，这种情况未考虑净截面属性，假定(a)荷载分布均匀；(b)截面在弯曲平面上有一个对称轴；(c)开孔位于构件深度的中三分之一及跨度的中二分之一；(d)任何两个相邻开孔的间距，以及从实测的纬圈到构件的纵轴的间距，其最小值为较大开孔的直径的2.5倍；(e)支座的最大剪应力不超过构件抗剪承载力设计值的50%。14.3.3.2Unreinforced circular openings may be located in the web of unstiffened prismatic Class 1 and Class 2 beams or girders without considering net section properties, provided that (a) the load is uniformly distributed; (b) the section has an axis of symmetry in the plane of bending; (c) the openings are located within the middle third of the depth and the middle half of the span of the member; (d) the spacing between the centres of any two adjacent openings, measured parallel to the longitudinal axis of the member, is a minimum of 2.5 times the diameter of the larger opening; and (e) the factored maximum shear at the support does not exceed 50% of the factored shear resistance of the section.14.3.3.3如果开孔处的力由弹性分析得出，所采用的步骤应以已出版的、公认的原理为依据。14.3.3.3 If the forces at openings are determined by an elastic analysis, the procedure adopted shall be in accordance with published, recognized principles. 14.3.3.4假设分析依据8.6节的(a)，(b)和(f)，构件开孔附近的强度和稳定性可以由塑性铰的假设位置所决定，以使由此而起的力分配满足力平衡的要求。然而，对于I型构件来说，假设腹板满足1类截面的宽厚比限制，翼缘的宽厚比可能会满足2类构件的要求。14.3.3.4 The strength and stability of the member in the vicinity of openings may be determined on the basis of assumed locations of plastic hinges, such that the resulting force distributions satisfy the requirements of equilibrium, provided that the analysis is carried out in accordance with Clause 8.6(a), (b), and (f). However, for I-type members, the width-to-thickness ratio of the flanges may meet the requirements of Class 2 sections, provided that the webs meet the width-to-thickness limit of Class 1 sections. 14.3.4 薄腹板对抵抗矩的影响当薄腹板的长细比超过，依据11节，翼缘应满足3类截面的宽厚比，而且梁或桁架的设计抵抗矩应由确定。其中等于13.5节或13.6节规定的设计抵抗矩，但不大于。除力矩之外，当一个轴向压力作用于桁架时，的表达式中的常数1900应该乘以因数。（参照11.2节）14.3.4 Effect of Thin Webs on Moment Resistance When the web slenderness ratio, , exceeds, the flange shall meet the width-to-thickness ratios of Class 3 sections in accordance with Clause 11, and the factored moment resistance of the beam or girder, ,shall be determined bywhere = factored moment resistance as determined by Clause 13.5 or 13.6 but not to exceed When an axial compressive force acts on the girder in addition to the moment, the constant 1900 in the expression for shall be reduced by the factor . (See also Clause 11.2.) 14.4 支承加劲肋14.4.1只要超出了腹板的支承阻力，在单腹板梁和桁架上，应在有集中荷载和反力的地方安装成对儿的支承加劲肋（见14.3.2节）。腹板的宽-厚比大于的单腹板桁架也应在未加外框的末端安装支承加劲肋。箱梁可以采用横隔梁来代替支承加劲肋。14.4 Bearing Stiffeners 14.4.1 Pairs of bearing stiffeners on the webs of single-web beams and girders shall be required at points of concentrated loads and reactions wherever the bearing resistance of the web is exceeded (see Clause 14.3.2). Bearing stiffeners shall also be required at unframed ends of single-web girders having web depth-to-thickness ratios greater than. Box girders may employ diaphragms designed to act as bearing stiffeners.14.4.2支承加劲肋应该能够负载翼缘或其借以获取荷载的翼缘，而且必须刚好达到翼缘板或翼缘角钢的边缘。依据13.3节，支承加劲肋应该设计成柱子，假设柱截面包括这一对加劲肋和一个位置居中、不大于内加劲肋厚度25倍的腹板条带，或者是当加劲肋位于腹板末端时不大于其厚度12倍的条带。在计算比值KL/r时，有效桩长KL应该不小于加劲肋长度的。只有角焊脚或翼缘腹板之外的加劲肋才是有效承载。角钢支承加劲肋不应卷曲。支承加劲肋应与腹板相连，以产生所需的力。这些力由加劲肋传入腹板，反之亦然。Bearing stiffeners shall bear against the flange or flanges through which they receive their loads and shall extend approximately to