预应力钢筋混凝土

In particular, the correlations between some characteristic size and the spectral response to a swept signal with all audible frequencies are presented here.

二者具有相当近似的形式，但尺寸不同，所用的材料也各异，前者是用砖石建成，后者是用木料建成，因此在整修前采用了许多预应力钢筋混凝土结构。

This design proposal is the prestressed reinforcement concrete conatant cross-section box shape continuous bridge, Main span disposal is 45+45+45m, the bridge floor width is 28m, the king post uses is the single box single room.

本设计方案为预应力钢筋混凝土等截面箱形连续梁桥，主桥布置为45+45+45m，梁桥面宽28m，采用单箱单室梁。

Its amount has relation with acting load. The influence on sectional curvature of bending components is the greatest one, the ultimate curvature of corroding section decrease obviously, and the sectional curvature increases rather sharply with the increase of rust rate during the process of corrosion. The anti-cracking capacity of prestressed bending R. C. components may be damage. For the convenience of engineering usage and damage evaluation of structure, this paper presents a concept of sectional damage coefficient on the foundation of experimental and treatment study.

试验与理论研究均表明，受压区钢筋锈蚀后对普通钢筋混凝土和预应力钢筋混凝土受弯构件的承载力影响均不大，但对构件的正常使用性能有较显著的影响，受压区钢筋锈蚀过程中，截面刚度有较显著的下降，挠度及受压区混凝土压应变随锈蚀量增加而增加，增加值与使用荷载大小有关；受弯构件的截面曲率所受影响最大，锈蚀后截面的极限曲率有明显的下降，在使用荷载作用下，截面曲率则随钢筋锈蚀量的增加而有较显著的增加；而预应力混凝土受弯构件的抗裂度会下降。

Use the finite element software ANSYS to make model for consecutive strands and unbonded prepressed concrete lining. Build the reciprocity relation of the cells in consecutive strands and cells in RC, analyse the stress and transmogrification of consecutive strands and RC to make sure the design parameter can meet the need of specification.

2采用有限元分析软件ANSYS，分别对无粘结预应力衬砌方案的预应力钢绞线和钢筋混凝土衬砌单独建模，预应力钢绞线的单元节点与钢筋混凝土单元间通过约束方程法建立起相互作用的关系，分析钢绞线和钢筋混凝土衬砌的应力和变形，计算结果表明确认采用的设计参数能够满足规范要求。

The use of unbonded tendons is now common in prestressed concrete structures, and they may be in the form of internal or external tendons.With the increasing use of unbonded tendons in both new construction and retrofitting of existing structures, there is the need for a closer look at their design and analysis.

采用无粘结预应力是现在常见的预应力钢筋混凝土结构，并且它们可能采取的形式是内部或外部tendons.with越来越多地使用无粘结预应力在这两个新的建设和改造现有的结构，有必要建立更密切看看他们的设计与分析。

Decades, the system does not always produce pipes, tiles, cement products and other traditional rod, but the development should be high (high-strength, high pressure) and large, new (new building materials and products) as a key to develop new products In detail: to develop high-strength prestressed concrete pile; apply to set up more than 110 kilovolt high voltage transmission lines and electrified railway lines, etc. Catenary large t m poles; application of new high-speed heavy rail with pre-stressed concrete sleeper; high-pressure , large-diameter prestressed concrete cylinder pipe; steel concrete and prestressed steel-concrete composite pipe; new type of reinforced concrete pipes, such as the mouth and socket bearing steel reinforced concrete pipes, square pipes, short-shaped pipes, common drains ; reinforced concrete inspection and; urban and rural construction using a variety of hollow interior wall panels and composite wall panels, concrete hollow block.

不能几十年一贯制生产管、瓦、杆等传统水泥制品，更应把发展高、大、新作为重点开发新产品，具体讲：大力发展预应力高强混凝土桩；适用于架设110 千伏以上高压输电线路和电气化铁路接触网线路等的大吨米电杆；适用高速重载铁路用的新型预应力混凝土轨枕；高压、大口径预应力钢筒混凝土管；钢板混凝土和预应力钢板混凝土复合管件；新型钢筋混凝土排水管，如钢承口和承插式钢筋混凝土排水管、方型渠、短形渠、共同渠；钢筋混凝土检查并；城乡建设用的各种空心内墙板和复合外墙板、混凝土空心砌块。

The structure design process of Macao Dome is introduced, and important analysis results and technical measures are presented. Key problems such as deep foundation in earth fill seashore, extra long prestressed concrete flat slab on the ground floor, large span ellipsoidal steel roof structure and its overall stability are discussed emphatically.

介绍了该项目的结构设计情况和主要的结构分析结果和重要的技术措施，着重讨论了填海地区的深基础、首层超长预应力钢筋混凝土大板、超大跨度椭球面钢屋盖体系及其整体稳定等结构设计中的关键技术。

Such parameters as the percentage of ordinary reinforcment, amounts and configuration of unbonded prestressed tendons, the ratio of span to depth and the loading patterns were considered. Based on the results, the fomula for the eqivalent length of deformation zone on the beams at ultimate were developed. A simple formula was developed for the ultimate mid-span deflection of concrete beams with concept of equivalent length of deformation zone, and the deformation of beam before internal reinforcement yielding was predicted by the traditional formula for the deformation of partically prestressed concrete beam. Then an analytical model was deduced for analyzing the ultimate stress increment in those concrete beams prestressed with external or internal unbonded tendons based on the mid-span deflection.(4) Testes were carried out on a thin-walled concrete box beam presressed with external CFRP tendons to study its short-term performances under uniform load, long-term behaviors under uniform load, and full-time performance under four-point load in turn.

3以体内非预应力钢筋配筋率、体外预应力筋配筋率、体外预应力筋布置形式、预应力度、跨高比、荷载形式等为参数，用非线性分析程序对体预应力筋混凝土梁进行了参数分析，依据分析结果提出了以综合配筋指标和预应力度为参数的等效变形区长度的计算公式，进而提出了基于等效变形区长度的极限挠度计算公式；体内非预应力钢筋屈服前的挠度计算采用常用的部分预应力混凝土梁挠度计算公式；依据试验和非线性数值计算结果，将不同转向块布置形式的体外预应力混凝土梁简化为跨中一个转向块的体外预应力混凝土梁，推导了基于跨中挠度的体外预应力筋应力增量的简化计算公式。

Such parameters as the percentage of ordinary reinforcment, amounts and configuration of unbonded prestressed tendons, the ratio of span to depth and the loading patterns were considered. Based on the results, the fomula for the eqivalent length of deformation zone on the beams at ultimate were developed. A simple formula was developed for the ultimate mid-span deflection of concrete beams with concept of equivalent length of deformation zone, and the deformation of beam before internal reinforcement yielding was predicted by the traditional formula for the deformation of partically prestressed concrete beam. Then an analytical model was deduced for analyzing the ultimate stress increment in those concrete beams prestressed with external or internal unbonded tendons based on the mid-span deflection.(4) Testes were carried out on a thin-walled concrete box beam presressed with external CFRP tendons to study its short-term performances under uniform load, long-term behaviors under uniform load, and full-time performance under four-point load in turn.

3以体内非预应力钢筋配筋率、体外预应力筋配筋率、体外预应力筋布置形式、预应力度、跨高比、荷载形式等为参数，用非线性分析程序对体预应力筋混凝土梁进行了参数分析，依据分析结果提出了以综合配筋指标和预应力度为参数的等活动房效变形区长度的计算公式，进而提出了基于等效变形区长度的极限挠度计算公式；体内非预应力钢筋屈服前的挠度计算采用常用的部分预应力混凝土梁挠度计算公式；依据试验和非线性数值计算结果，将不同转向块布置形式的体外预应力混凝土梁简化为跨中一个转向块的体外预应力混凝土梁，推导了基于跨中挠度的体外预应力筋应力增量的简化计算公式。

The results indicated that UFA has the effects of dense packing, water reducing and strength increasing .

结果表明，UFA有减水增强和密实填充效果；以25%的UFA等量取代水泥，成功配制了铁路预应力钢筋混凝土试验梁工程的高性能混凝土。

Cynanchum Lingtai apricot production in the average weight 65 grams, the brightly-colored fruit, juicy rich, sweet-sour taste, sweet from the nucleolus, when the late Qing Dynasty famous Shaanxi, Gansu provinces, the Qing imperial court Tongzhi tribute for years.

灵台生产的牛心杏平均单果重65克，果实色泽鲜艳，汁多味浓，甜酸适口，离核仁甜，清末时就驰名陕、甘两省，清同治年间曾为朝廷贡品。

Chenopodium album,Solanum nigrum, and Amaranthus retroflexus were very susceptible to the herbicides. Polygonum persicaria and Abutilon theophrasti were relatively less susceptible to the herbicides, and Lycopersicon esculentum was not susceptible to it. The relationship between reduction rates of weed biomass and PPM values of weed leaves 2,4, and 6 days after treatment was established.

供试的6种杂草对该混剂的敏感性存在显著差异：红心藜Chenopodium album、龙葵Solanum nigrum和反枝苋Amaranthus retroflexus对该混剂最敏感，ED90值分别为47.65、71.67和29.17g/hm2；春蓼Polygonum persicaria和苘麻Abutilon theophrasti敏感，ED90值分别为96.91、114.20g/hm2；而番茄不敏感。