鋼筋混凝土框架結(jié)構(gòu)設(shè)計的幾點心得體會

1、鋼筋混凝土框架結(jié)構(gòu)設(shè)計的幾點心得體會張永濤 姬廣東（山東省冶金設(shè)計院有限責(zé)任公司 萊蕪 271104）摘要：在鋼筋混凝土結(jié)構(gòu)設(shè)計中，每個設(shè)計者的經(jīng)驗不同，對規(guī)范的理解不同，所以在處理某個設(shè)計問題時，也就會采取不同的處理方法。對于鋼筋混凝土框架結(jié)構(gòu)設(shè)計中，基礎(chǔ)、梁、柱、板四部分應(yīng)注意的問題，分別提出了幾點看法。關(guān)鍵詞：結(jié)構(gòu)設(shè)計基礎(chǔ)梁柱板 現(xiàn)在越來越多的建筑物使用鋼筋混凝土結(jié)構(gòu)，故鋼筋混凝土結(jié)構(gòu)在整個建筑市場起到越來越重要的地位。在鋼筋混凝土結(jié)構(gòu)設(shè)計中，每個設(shè)計者的經(jīng)驗不同，對規(guī)范的理解不同，所以在處理某個設(shè)計問題時，也就會采取不同的處理方法。在這十年的結(jié)構(gòu)設(shè)計工作中，本人也積累了一些經(jīng)驗，下面就

2、鋼筋混凝土框架結(jié)構(gòu)設(shè)計中的基礎(chǔ)、梁、柱、板四部分，在設(shè)計時應(yīng)注意的問題，闡述一下個人觀點。1.基礎(chǔ)部分1.1對于柱下擴展基礎(chǔ)寬度較寬(大于4米)或地基不均勻及地基較軟時宜采用柱下條基。并應(yīng)考慮節(jié)點處基礎(chǔ)底面積雙向重復(fù)使用的不利因素，適當(dāng)加寬基礎(chǔ)。1.2建筑地段較好，基礎(chǔ)埋深大于3米時，應(yīng)建議甲方做地下室。當(dāng)?shù)鼗休d力滿足設(shè)計要求時，地下室底板可不再外伸以利于防水。每隔3040米設(shè)一后澆帶，并注明兩個月后用微膨脹混凝土澆注。設(shè)置地下室可降低地基的附加應(yīng)力，提高地基的承載力(尤其是在周圍有建筑時有用)，減少地震作用對上部結(jié)構(gòu)的影響。不應(yīng)設(shè)局部地下室，且地下室應(yīng)有相同的埋深。1.3地下室外墻為混凝土

3、時，相應(yīng)的樓層處梁和基礎(chǔ)梁可取消。1.4抗震縫、伸縮縫在地面以下可不設(shè)，連接處應(yīng)加強。但沉降縫兩側(cè)墻體基礎(chǔ)一定要分開。1.5新建建筑物基礎(chǔ)不宜深于周圍已有基礎(chǔ)。如深于原有基礎(chǔ)，其基礎(chǔ)間的凈距應(yīng)不少于基礎(chǔ)高差的2倍，否則應(yīng)打抗滑移樁，防止原有建筑的破壞。建筑層數(shù)相差較大時，應(yīng)在層數(shù)較低的基礎(chǔ)方格中心的區(qū)域內(nèi)墊焦碴來調(diào)整基底附加應(yīng)力。1.6獨立基礎(chǔ)偏心不能過大，必要時可與相近的基礎(chǔ)做成柱下條基。柱下條形基礎(chǔ)的底板偏心不能過大，必要時可作成三面支承一面自由板(類似筏基中間開洞)。兩根柱的柱下條基的荷載重心和基礎(chǔ)底版的形心宜重合，基礎(chǔ)底板可做成梯形或臺階形，或調(diào)整挑梁兩端的出挑長度。1.7獨立基礎(chǔ)的拉

4、梁宜通長配筋，其下應(yīng)墊焦碴。拉梁頂標(biāo)高宜較高，否則底層墻體過高。1.8底層內(nèi)隔墻一般不用做基礎(chǔ)，可將地面的混凝土墊層局部加厚。1.9考慮到一般建筑沉降為鍋底形，結(jié)構(gòu)的整體彎曲和上部結(jié)構(gòu)與基礎(chǔ)的協(xié)同作用，頂、底板鋼筋應(yīng)拉通(多層的負(fù)筋可截斷1/2或1/3)，且縱向基礎(chǔ)梁的底筋也應(yīng)拉通。1.10基礎(chǔ)底板混凝土不宜大于c3o，一是沒用，二是容易出現(xiàn)裂縫。1.11基礎(chǔ)底面積不應(yīng)因地震附加力而過分加大，否則地震下安全了而常規(guī)情況下反而沉降差異較大，本末倒置。免費論文下載中心2.柱部分2.1地上為圓柱時，地下部分應(yīng)改為方柱，方便施工。圓柱縱筋根數(shù)最少為8根，箍筋用螺旋箍，并注明端部應(yīng)有一圈半的水平段。方柱

5、箍筋應(yīng)使用井字箍，并按規(guī)范加密。角柱、樓梯間柱應(yīng)增大縱筋并全柱高加密箍筋。幼兒園不宜用方柱。 2.2原則上柱的縱筋宜大直徑大間距，但間距不宜大于200。 2.3柱內(nèi)埋管，由于梁的縱筋錨入柱內(nèi)，一般情況下僅在柱的四角才有條件埋設(shè)較粗的管。管截面面積占柱截面4%以下時，可不必驗算。柱內(nèi)不得穿暖氣管。 2.4柱斷面不宜小于450450，混凝土不宜小于c25，否則梁縱筋錨入柱內(nèi)的水平段不容易滿足0.45la的要求，不滿足時應(yīng)加橫筋；否則在梁柱節(jié)點處鋼筋太密，混凝土澆筑困難。異型柱結(jié)構(gòu)，梁縱筋一排根數(shù)不宜過多，柱端部縱筋不宜過密，否則節(jié)點混凝土澆筑困難。當(dāng)有部分矩形柱部分異型柱時，應(yīng)注意異型柱的剛度要和

6、矩形柱相接近，不要相差太大。2.5柱應(yīng)盡量采用高強度混凝土來滿足軸壓比的限制，減小斷面尺寸。 2.6盡量避免短柱，短柱箍筋應(yīng)全高加密，短柱縱筋不宜過大。 2.7考慮到豎向地震作用，柱子的軸壓比及配筋宜留有余地。2.8獨立柱上或柱的中部（半層處）有挑梁時，挑梁長度應(yīng)有限制。3.梁部分 3.1梁上有次梁處(包括挑梁端部)應(yīng)附加箍筋和吊筋，宜優(yōu)先采用附加箍筋。附加筋一般要有，但不應(yīng)絕對。規(guī)范說的清楚，位于梁下部或梁截面高度范圍內(nèi)的集中荷載，應(yīng)全部由附加橫向鋼筋承擔(dān)。也就是說，位于梁上的集中力如梁上柱、梁上后做的梁如水箱下的墊梁不必加附加筋。位于梁下部的集中力應(yīng)加附加筋。但梁截面高度范圍內(nèi)的集中荷載可

7、根據(jù)具體情況而定。當(dāng)主次梁截面相差不大，次梁荷載較大時，應(yīng)加附加筋。當(dāng)主梁高度很高，次梁截面很小、荷載很小時，如快接近板上附加暗梁，主梁可不加附加筋。還有當(dāng)主次梁截面均很大，如工藝要求形成的主次深梁，而荷載相對不大，主梁也可不加附加筋。 3.2當(dāng)外部梁跨度相差不大時，梁高宜等高，尤其是外部的框架梁。當(dāng)梁底距外窗頂尺寸較小時，宜加大梁高做至窗頂。外部框架梁盡量做成外皮與柱外皮平齊。梁也可偏出柱邊一較小尺寸。梁與柱的偏心可大于1/4柱寬，并宜小于1/3柱寬。3.3梁上有次梁時，應(yīng)避免次梁搭接在主梁的支座附近，否則應(yīng)考慮由次梁引起的主梁抗扭，或增加構(gòu)造抗扭縱筋和箍筋。當(dāng)采用現(xiàn)澆板時，抗扭問題并不嚴(yán)重

8、。 3.4原則上梁縱筋宜小直徑小間距，有利于抗裂，但應(yīng)注意鋼筋間距要滿足要求，并與梁的斷面相應(yīng)。箍筋按規(guī)定在梁端頭加密。布筋時應(yīng)將縱筋等距，箍筋肢距可不等。小斷面的連續(xù)梁或框架梁，上、下縱筋均應(yīng)采用同直徑的，盡量不在支座搭接。3.5端部與框架梁相交或彈性支承在墻體上的次梁，梁端支座可按簡支考慮，但梁端箍筋應(yīng)加密。3.6上反梁的板吊在梁底下，板荷載宜由箍筋承受，或適當(dāng)增大箍筋。梁支承偏心布置的墻時宜做下挑沿。3.7挑梁宜作成等截面(大挑梁外露者除外)。與挑板不同，挑梁的自重占總荷載的比例很小，作成變截面不能有效減輕自重。變截面挑梁的箍筋，每個都不一樣，難以施工。變截面梁的撓度也大于等截面梁。挑梁

9、端部有次梁時，注意要附加箍筋或吊筋。一般挑梁根部不必附加斜筋，除非受剪承載力不足。對于大挑梁，梁的下部宜配置受壓鋼筋以減小撓度。挑梁配筋應(yīng)留有余地。免費論文下載中心3.8梁上開洞時，不但要計算洞口加筋，更應(yīng)驗算梁洞口下偏拉部分的裂縫寬度。梁從構(gòu)造上能保證不發(fā)生沖切破壞和斜截面受彎破壞。3.9挑梁出挑長度小于梁高時，應(yīng)按牛腿計算或按深梁構(gòu)造配筋。3.10扁梁寬度不必過大，只要鋼筋能正常擺下及受剪滿足即可。因為在撓度計算時，梁寬對剛度影響不大，加寬一倍，撓度減小20%左右。相對來講，增大鋼筋更經(jīng)濟，鋼筋加大一倍，撓度減小60%左右，同時梁的上筋應(yīng)大部分通長布置，以減小混凝土徐變對撓度的增大，如果上

10、筋不小于下筋，撓度減小20%。 3.11當(dāng)一寬框架梁托兩排間距較小的柱時，可加一剛性挑梁，兩個柱支承在剛性挑梁的端頭。 3.12梁寬大于350時，應(yīng)采用四肢箍。4.現(xiàn)澆板部分4.1板的鋼筋宜采用大直徑大間距，但間距不大于200，間距盡量用200。(一般跨度小于6.6米的板的裂縫均可滿足要求)。板上下鋼筋間距宜相等，直徑可不同，但鋼筋直徑類型也不宜過多。4.2相連幾個房間的同型號同間距板底鋼筋宜連通。4.3配筋計算時，可考慮塑性內(nèi)力重分布，將板上筋乘以0.80.9的折減系數(shù)，將板下筋乘以1.11.2的放大系數(shù)。出處：中國經(jīng)濟與管理科學(xué)2009年第7期structure design of rei

11、nforced concrete framezhang yongtao ji guangdong(shandong province metallurgical design institute co., ltd. laiwu 271104)abstract: in the reinforced concrete structure design, each designers experience is different, different understanding of norms, so in dealing with a certain design issues, it wou

12、ld take a different approach. for the design of reinforced concrete frame structure, foundations, beams, columns, boards should pay attention to the issue of four parts, respectively, made a few observations. keywords: structural design of foundation beam plate more and more buildings to use reinfor

13、ced concrete structure, reinforced concrete structure and therefore the entire construction market play an increasingly important role. in the reinforced concrete structural design, each designers experience is different, different understanding of norms, so in dealing with a certain design issues,

14、it would take a different approach. in this decade, the structural design work, i have accumulated some experience, the following on the design of reinforced concrete frame structure, the foundation, beams, columns, panels of four parts in the design should pay attention to the problem, elaborate pe

15、rsonal views.1.the fundamental elements ofthe expansion of the basis for the column width under a wide (greater than 4 meters) or the uneven ground and foundation should be adopted when compared with the soft base of the next column. and should consider the basis of node size at the end of a two-way

16、 repeated use of unfavorable factors, appropriate widening base. 1.2 building lot better basis for depth greater than 3 meters, should recommend to the party to do the basement. bearing capacity of the local base to meet the design requirements, the basement floor can be no overhang to facilitate wa

17、ter. every 30 40 meters is located one after the pouring zone, and indicate the two months after the pouring of concrete with micro-expansion. setting the foundation of the basement can reduce the additional stress, improve the bearing capacity of foundations (especially in the construction around w

18、hen useful) to reduce the role of the upper structure of the earthquake impact. should not be any partial basement, and the basement should have the same depth.1.3 for the concrete basement wall, the corresponding floor beams and foundation beams at cancel. 1.4 earthquake seam, expansion joints on t

19、he ground below may from time to set up, connections should be strengthened. however, the basis of settlement joint on both sides of the wall must be separated. the basis of 1.5 new buildings should not be darker than the surrounding existing basis. as deeply as the original foundation, based on the

20、 basis of inter-spacing of not less than 2 times the height difference, or to fight anti-sliding pile should be to prevent the destruction of the original building. larger difference between the construction layers should be the basis of the lower layers within the region grid center ballast to adju

21、st the base pad coke additional stress. 1.6 independence-based bias can not be too large, if necessary, the foundation made with similar articles under column base. column strip foundation under the floor can not be too eccentric, if necessary, could be made on three sides, supporting one side of fr

22、ee (similar to the raft-based intermediate open hole). column 2 column article under the base load center of gravity and centroid-based bottom plate should overlap the foundation floor or stairs can be made into trapezoidal shape, or adjusting the length of cantilever beam at both ends of chutiao. 1

23、.7 independence-based pull-liang yi-length reinforcement, under which should focus ballast mat. top elevation should pull high beam, or the bottom of the wall is too high. 1.8 in the bottom wall generally do not have to do based on the concrete floor cushion can be partially thickened. 1.9 taking in

24、to account the general settlement of the bottom of the pot-shaped building, the structure of the overall bending and the upper structure and the basis of synergies, top and bottom reinforcement should be raton (multi-layer of negative reinforcement can be cut off 1 / 2 or 1 / 3), and the foundation

25、beam bottom longitudinal reinforcement should also be raton. 1.10 foundation slab of concrete should not be larger than c3o, one useless the second is prone to cracks. 1.11 the foundation area should not unduly increase the earthquake additional force, otherwise the next earthquake safety, rather th

26、e contrary, the settlement, under normal circumstances are quite different cart before the horse. reposted elsewhere in the paper for free download 2. column part of the 2.1 on the ground for the cylinder, the underground portion should be replaced by square columns, to facilitate construction. colu

27、mn longitudinal reinforcement root number at least 8, stirrup with spiral bands, and indicate the end of the horizontal segment should have a lap and a half. square columns tic-tac-hoop stirrups should be used, in accordance with standard encryption. corner column, stair column longitudinal reinforc

28、ement should be increased, and the whole column stirrups high encryption. kindergarten should not use the square column. 2.2 in principle, the vertical column reinforcement should large-diameter large spacing, but the pitch should not be larger than 200. 2.3 column pipe, due to the beam longitudinal

29、 reinforcement anchored into the column, the general only in the column under the conditions laid four corners have thick tube. tube-sectional area of column cross section accounted for less than 4%, it can not checking. column shall not clothing trachea. 2.4 column cross-section should not be less

30、than 450 ?450, concrete should not be less than the c25, otherwise the beam longitudinal reinforcement anchored into the column level within the segment is not easy to satisfy the requirements of 0.45la, does not meet the horizontal bars should be added; otherwise reinforced beam-column nodes are to

31、o dense, concrete placement difficult. special-shaped column structure, and beam longitudinal reinforcement should not be too much root number in a row and column longitudinal reinforcement ends should not be too dense, otherwise the node concrete placement difficult. when there is some part of the

32、rectangular column-shaped columns, they should pay attention to special-shaped columns and rectangular column stiffness was similar and not that much difference. 2.5 column should be using high-strength concrete to meet the axial load ratio limits, reduce the section size. 2.6 try to avoid short col

33、umns, short columns stirrup should be full of high encryption, short column longitudinal reinforcement should not be too large. 2.7 taking into account the role of vertical earthquake, columns under axial compression ratio and reinforcement should leave some leeway. 2.8 independent of the central co

34、lumn or columns (semi-floor office) are cantilever beam, the cantilever beam length should be limited. 3. liang part of the 3.1 beam with sub-beam department (including the cantilever beam ends) should be attached stirrups and hanging bars, should give priority to adopt additional stirrups. addition

35、al tendons in general should be, but not absolute. a clear specification that is located in the lower beam or high beam within the scope of the concentrated load shall be borne entirely by additional transverse reinforcement. in other words, the concentration of power in the beam, such as beam colum

36、ns, beams after the beam to do under the pad-like water tanks do not have to add additional muscle. is located in the lower beam of concentration should be added additional reinforcement. however, a high beam within the concentrated load can be determined according to specific circumstances. when th

37、e primary and secondary beam cross-section more or less, sub-beam load is large, additional reinforcement should be added. when the main beam at very high altitudes, sub-beam cross-section is very small, load is very small, such as the approach the board added the dark beam, main beam may from time

38、to add additional muscle. there were significant when the primary and secondary beam, such as the process requires the formation of the primary and secondary deep beam, while the load is relatively small, the main beam or not to add additional muscle. 3.2 when the external beam span or less, liang g

39、ao yi high, especially outside the frame beam. when the beam away from the outer windows of the top end of small size, it is desirable to do to increase the beam window of a high top. as far as possible outside the framework of beams and columns made of skin skin flush. liang-chu, may also be missed

40、 while a smaller size. eccentric beam-column may be greater than 1 / 4 columns wide and appropriate less than 1 / 3 of column width. there are times when the beam 3.3 beam should avoid secondary beam overlap in the vicinity of the main beam of the bearing, otherwise, consideration should be given by

41、 the second torsion beam caused by the main beam, or increasing the longitudinal reinforcement and stirrup torsional structure. when using in-situ plate, the torsion problem is not serious. 3.4 in principle, small-diameter beam longitudinal reinforcement should a small spacing is conducive to cracki

42、ng, but it should be noted that reinforcement spacing to meet the requirements, and with the corresponding cross-section of beam. stirrups at the end of the beam according to the provisions of the first encryption. fabric reinforcement should be equidistant longitudinal reinforcement, stirrups, etc.

43、 from time away from the limb. small cross-section of a continuous beam or frame beams, the upper and lower longitudinal reinforcement should be using the same diameter as much as possible not to overlap bearings. 3.5 end with the frame beams intersect, or elastic support at the wall on the sub-beam

44、s, simply supported beam end bearing may be considered, but the end of the beam stirrups should be encrypted. 3.6 the panel of anti-beam suspended beneath the beam, plate load appropriate for the stirrups to bear, or an appropriate increase in stirrup. eccentric arrangement of beams supporting the w

45、alls along the opportune time to do the next pick. 3.7 pick liang yiross-section (large cantilever beam except those exposed). and pick a different panel to pick the beam weight ratio of the total load is small, ariable cross-section can not effectively reduce weight. variable cross-section cantilev

46、er beam of the stirrups, each is different and difficult construction. variable cross-section beam deflection is also greater than the other beam. cantilever beam with secondary beam end, attention should be attached stirrups or hanging bars. generally do not have to add the root of cantilever beam

47、oblique muscle, unless the lack of shear strength. for large cantilever beam, the beam bottom reinforcement should configure the compression to reduce the deflection. cantilever beam reinforcement should leave room for the. reposted elsewhere in the paper for free download 3.8 beam openings, not onl

48、y to calculate the hole reinforcement, hole should be checking under the partial pull-beam part of the crack width. beams from the structure does not occur on the punching can guarantee the damage and oblique cross-section flexural damage. 3.9 chutiao cantilever beam is less than the length of beam is high, should be calculated or bracket structure reinforced