sr用鋼管樁和貝雷片做現(xiàn)澆箱梁施工支架施工實(shí)踐

1、Good is good, but better carries it.精益求精，善益求善。sr用鋼管樁和貝雷片做現(xiàn)澆箱梁施工支架施工實(shí)踐用鋼管樁和貝雷片做現(xiàn)澆箱梁施工支架施工實(shí)踐畢 業(yè) 論 文鋼管樁和貝雷片做現(xiàn)澆箱梁支架施工實(shí)踐中鐵二十三局集團(tuán)第一工程有限公司鐘本鋒目 錄1.引言32.現(xiàn)澆支架比較32.1軍用墩與軍用梁組合現(xiàn)澆支架32.2貝雷片和抱箍構(gòu)成移動式支架32.3腳手架、萬能桿件或軍用墩與型鋼支架32.4鋼管樁、貝雷片和碗扣件支架42.5鋼管樁與貝雷片支架 圖 443.工程實(shí)例43.1工程概況43.2支架的設(shè)計和施工43.2.1貝雷桁架的設(shè)計43.2.1.1貝雷片的布置53.2.1.

2、2貝雷桁架的設(shè)計檢算5強(qiáng)度檢算53.2.2貝雷片的安裝和拆除63.2.2.1鋼管樁支墩的設(shè)計63.2.2.2鋼管的布置63.2.2.3鋼管排架的設(shè)計檢算63.2.2.4鋼管排架的拆除73.3支架預(yù)壓83.3.1預(yù)壓施工及成果分析83.3.2對桁架的改進(jìn)措施83.3.3預(yù)拱度設(shè)置83.4混凝土的澆注93.4.1混凝土的澆注順序93.4.2沉降觀測結(jié)果分析94.體會104.1主要優(yōu)點(diǎn)104.2存在的不足和需進(jìn)一步改進(jìn)的問題10鋼管樁和貝雷片做現(xiàn)澆箱梁支架施工實(shí)踐中鐵二十三局集團(tuán)第一工程有限公司 鐘本鋒內(nèi)容提要：在軟弱地基上使用鋼管樁和貝雷片做為現(xiàn)澆支架，避免了處理軟基，克服了地基沉降對現(xiàn)澆箱梁施工

3、線形的影響；結(jié)合支架施工實(shí)例，著重介紹鋼管排架和貝雷片組成的支架構(gòu)造和施工。關(guān)鍵詞：鋼管樁和貝雷片 支架 實(shí)踐1.引言在軟弱地基上施工橋梁上部現(xiàn)澆梁、板，一般的施工方法是對軟基進(jìn)行加固處理，然后搭設(shè)滿堂支架施工。由于軟弱地基特殊的地質(zhì)條件，地基處理難度較大；同時由于處理厚度的不均勻性，當(dāng)填加施工荷載時，地基將可能出現(xiàn)不均勻的沉降，從而可能對混凝土的質(zhì)量造成不同程度的損傷，對工程質(zhì)量留下隱患。且地基處理為一次性投入，處理費(fèi)用高，周轉(zhuǎn)利用率低。隨著工程技術(shù)的發(fā)展，人們在工程實(shí)踐中摸索出減少或避免處理地基的施工方法，使支架越發(fā)安全可靠。2.現(xiàn)澆支架比較盡可能地利用既有墩臺基礎(chǔ)，以避免或減少處理地基，

4、根據(jù)使用器材的不同，在實(shí)踐中逐步摸索出幾種現(xiàn)澆支架模式，可用在軟地基基礎(chǔ)上。列舉其中的部分結(jié)構(gòu)形式如下。2.1軍用墩與軍用梁組合現(xiàn)澆支架支架基本形式見圖1。軍用梁承載力強(qiáng)，根據(jù)不同跨度在孔間設(shè)置支墩，可拼裝出不同跨度的支架，但由于為制式器材，在器材型號不全時，跨度拼裝將受到很大限制；軍用梁自重大、對支撐墩和基礎(chǔ)要求較高。該支架在青島流亭立交橋、濟(jì)青高速公路后劉立交橋等橋梁現(xiàn)澆梁施工中先后得到應(yīng)用。2.2貝雷片和抱箍構(gòu)成移動式支架利用貝雷片拼裝成支撐橫梁和縱梁，抱箍固定在橋梁墩身上，作為體系的承重構(gòu)件，利用卷揚(yáng)機(jī)拖動縱梁前移，實(shí)現(xiàn)可移動式現(xiàn)澆支架。見圖2。該支架形式在廣東肇慶大橋北岸連續(xù)箱梁施工

5、中得到應(yīng)用。支架結(jié)構(gòu)簡單，受力明確，操作簡便；缺點(diǎn)是適用跨度較小，適用于圓柱形墩，混凝土施工過程較復(fù)雜。2.3腳手架、萬能桿件或軍用墩與型鋼支架用腳手架或萬能桿件搭設(shè)支墩，采用型鋼組成作為現(xiàn)澆支架，根據(jù)型鋼的不同型號可根據(jù)要求做成不同跨度的支架。較常用的支架跨度一般在6M左右，跨度較大的可用至9M。結(jié)構(gòu)形式見圖3。使用較靈活，但支墩基礎(chǔ)較密，處理費(fèi)用相對較高。2.4鋼管樁、貝雷片和碗扣件支架利用鋼管將貝雷片架立地面，然后在貝雷架上支立碗扣件，構(gòu)成支架。該種支架利用貝雷片代替地基處理，材料周轉(zhuǎn)利用率高，適用性強(qiáng)，安全可靠，但材料投入較大。結(jié)構(gòu)形式見圖4。2.5鋼管樁與貝雷片支架 圖 4根據(jù)現(xiàn)澆構(gòu)

6、造物的高度，將鋼管樁制作成排架形式，做為支架的支撐墩，上部用貝雷片拼裝成連續(xù)梁式桁架。用固定在貝雷片主弦桿上的方木做標(biāo)高調(diào)整構(gòu)件。該支架的特點(diǎn)是：支架材料投入少，重量輕，施工機(jī)械化程度高，適用的跨度相對較大。結(jié)合工程實(shí)例對該種支架重點(diǎn)介紹。3.工程實(shí)例3.1工程概況通啟高速公路陳橋互通立交主線橋，位于江蘇省南通市，地處長江三角洲沖積平原，地層為第四系全新系統(tǒng)及上更新系統(tǒng)，表層分布1.56.5M厚的軟塑狀亞粘土，下臥軟塑狀亞砂土，軟土地基多埋藏在地表下10M以內(nèi)，地基承載力較差。大橋上部結(jié)構(gòu)為現(xiàn)澆連續(xù)箱梁，分左右兩個半幅。箱梁為單箱雙室斷面，標(biāo)準(zhǔn)斷面尺寸見圖5。橋墩高度為611M。跨徑20M，

7、基礎(chǔ)為樁柱式柔性墩。 3.2支架的設(shè)計和施工 鋼管支架設(shè)計主要要解決兩方面的問題：一是臨時支墩的結(jié)構(gòu)形式，二是由貝雷片組成的桁架整體強(qiáng)度、剛度和穩(wěn)定性。下面著重就這兩方面的問題進(jìn)行分析探討。使用的主要材料為：直徑273 mm，壁厚6mm的鋼管；321型的貝雷片（高1.5M，每節(jié)長3.0M）。3.2.1貝雷桁架的設(shè)計現(xiàn)澆支架的整體布置形式見圖6。圖63.2.1.1貝雷片的布置貝雷片的結(jié)構(gòu)布置形式見圖7。沿箱梁橫斷面方向設(shè)置9道貝雷片，均勻布置。桁架頂部橫向布設(shè)10×12CM的方木，間距30CM，用鐵絲或鐵釘與貝雷片主弦桿綁扎牢靠（預(yù)先在貝雷片主弦桿上綁扎調(diào)整方木）；方木在箱室肋部加密一

8、半，間距為15CM；方木長度為3M交錯布置，并使位于同一貝雷片上的方木接頭不超過通過該貝雷片方木總面積的50%，做為底模板橫肋，兼做貝雷片的上水平聯(lián)；沿支架縱向每2.8M設(shè)置橫向鋼結(jié)構(gòu)連接系一道，以保證9道貝雷片整體受力。為保證貝雷片的整體穩(wěn)定，在位于箱梁兩外側(cè)豎肋的三片桁架底部用75×8角鋼與橫向連接系焊接，組成下水平聯(lián)。見圖8。3.2.1.2貝雷桁架的設(shè)計檢算施工荷載主要由鋼筋砼自重q1、模板自重q2、貝雷桁架自重q3、施工荷載q4構(gòu)成。支架承受的總荷載為：q=q1+q2+q3+q4 =229.5KN/m。強(qiáng)度檢算 貝雷架縱向布置形式為間距6米和14米間隔布置的連續(xù)梁，最不利情況

9、發(fā)生在14米跨度內(nèi)混凝土全部澆注完成，其它跨徑內(nèi)沒有荷載時。按簡支梁計算。則最大彎距：Mmax=qL2/8=229.5×142/8=5621.5KN·M，單片貝雷架承受最大彎距（按荷載橫向均勻分布計算，不考慮不均勻分布系數(shù)）：M=Mmax/9 =5621.5/9=624.6 <M=975 KN·M,滿足要。撓度檢算因貝雷片每節(jié)結(jié)構(gòu)形式相同，可看作勻質(zhì)梁，并以簡支梁模型檢算，最大撓度為：f=（5/384）qL4/（EIIx）=(5/384)×229.5×14004/（2.1×106×250500×9）=2.4c

10、mL/400=1400/400=3.5cm滿足施工要求（其中貝雷架的慣性矩Ix=250500cm4）。3.2.2貝雷片的安裝和拆除將每5片貝雷片拼裝成整體桁架，用16t吊車起吊就位；一聯(lián)全部貝雷片安裝完畢，加設(shè)橫向支撐、上平聯(lián)和下平聯(lián)。貝雷桁架采用整體落架法拆除。在貝雷桁架的底部（近支墩處）各設(shè)一根橫梁，橫梁用20T手拉葫蘆懸吊在箱梁翼緣板承托上（在承托上預(yù)留懸吊孔），落架時先拆除支墩，再拆除桁架的平聯(lián)，拔掉貝雷片間的連接銷子，松動手動葫蘆貝雷桁架脫模下落。3.2.2.1鋼管樁支墩的設(shè)計支墩排架的基本結(jié)構(gòu)形式見圖9。3.2.2.2鋼管的布置主要解決的問題是：在保證每排排架承載能力的前提下，保證

11、鋼管樁的整體穩(wěn)定性和抗傾覆能力。具體措施：鋼管樁頂部與工字鋼焊接牢靠，底部與預(yù)埋鋼板焊接，沿鋼管高度方向每4M用14焊接一道橫向連接撐，構(gòu)成一個排架；將同一個承臺上的兩個排架頂部用14連接，形成上平聯(lián)，兩排間用3道14連接成人字撐。使兩個排架形成一個受力整體，增強(qiáng)抗傾覆能力。3.2.2.3鋼管排架的設(shè)計檢算9.003.381.69×43.381.11.1按如下不利條件假定荷載:每兩個排架承受跨度為23M的箱梁鋼筋砼重量,并按簡支梁模型計算支反力。作用在排架上的荷載構(gòu)成如下：鋼筋砼重力q1、工字鋼自重q2、其他荷載q3，則每個排架承受的總荷載為：P= q1q2q3=2645.5KN由于

12、每個排架承受的總荷載由9道貝雷片均勻分部在工字鋼上，每處荷載為：q=P/9=294KN。荷載布置如圖10。將每個排架看作剛架計算,并按鋼管最大高度9.0M計算。上述剛架為對稱剛架,取一半研究，采用力矩分配法計算。 圖10。CDCGCBBCBFBA14.9 -33.3 0.7 32.5 129.2 -3.3 -125.97.3 -7.3-0.5-0.5 0 -0.90.1 2.7.-2.8-0.4 0 -0.91561.5 31.1-2.5-4.9 0.2 9.8-30.129.7 0.7 29.7-60.1-60.1 -2.9 -120.259.25.7 118.3124-124GFEDCBA

13、AEAB0.0460.9540.3280.0160.6560.4940.0120.494-5.1 -0.2 -10.3-5.21.32.6 0 2.61.31.414.916.2I45b工字鋼轉(zhuǎn)動慣量為:I1=33.759×1074; 273,壁厚6鋼管轉(zhuǎn)動慣量為:I2=44.848×106,材料相同為A3鋼,彈性模量相同。計算各節(jié)點(diǎn)的分配系數(shù)、計算過程見圖11。圖11固端彎矩MAB=-ql/8=294×3.375/8=-124KN·M,MBA=-MAB=124KN·M由各節(jié)點(diǎn)的彎矩和外力,根據(jù)力矩平衡可得節(jié)點(diǎn)剪力;由計算出的剪力,根據(jù)節(jié)點(diǎn)力的

14、平衡原理可得各桿的軸力（壓力）如下:NAE=405.6KN, NBF=571.4KN,NCG=170.8KN, N中=351.8KN鋼管強(qiáng)度檢算：取壓力最大桿件BF,桿件自由長度為4M，視為兩端鉸接桿，其柔度=L/r=1×4000/94.4=42.4 查表可得=0.89，則鋼管樁的穩(wěn)定強(qiáng)度為：= N/(A)=571.4×103÷（5030 ×0.89）=127.6MPa<=170 MPa滿足要求。鋼橫梁檢算：鋼橫梁實(shí)際有7個支點(diǎn)，按5個支點(diǎn)計算。其中5道貝雷架架設(shè)在鋼管樁樁頂，其余4道架設(shè)在跨中，鋼橫梁為4跨連續(xù)梁,查表得:Mmax=(0.1998

15、-0.0368+0.0101-0.003)×Pl=168.8KN·mW=M/W=1206cm3< W I45b= 1500.4cm,故選用45b工字鋼滿足施工要求。3.2.2.4鋼管排架的拆除為保證排架受力的整體性，不使用砂箱等落架構(gòu)件，采用直接割除鋼管落架。具體做法是：將排架頂部的工字鋼用鋼絲繩和手拉葫蘆吊在桁架上，用氣割將鋼管根部與預(yù)埋件割開，慢慢放松手拉葫蘆將排架拆除，整體移至另半幅。3.3支架預(yù)壓3.3.1預(yù)壓施工及成果分析加載采用周圍圍砂袋中間裝散砂的方法，模擬施工荷載。因砼分兩次施工，預(yù)拱度參照支架在箱梁80%自重時產(chǎn)生的變形設(shè)置。加載前，沿模板縱橫向每5

16、M開設(shè)40×40CM活動孔一個，預(yù)壓結(jié)束時將運(yùn)輸車開到活動孔處，將砂子直接泄至車內(nèi)。加載總重量為23M跨度箱梁自重。沉降觀測結(jié)果見表1?？梢钥闯鰧?shí)測彈性變形與計算值基本相符，但在支架跨中出現(xiàn)了不均勻沉降，需進(jìn)一步采取加固措施。3.3.2對桁架的改進(jìn)措施通過預(yù)壓觀測成果分析，跨中出現(xiàn)了橫向不均勻沉降。由于貝雷片跨中所受的彎矩較大，荷載出現(xiàn)了橫向不均勻分布，原設(shè)計的橫向加固結(jié)構(gòu)未達(dá)到預(yù)想效果。為保證箱梁的線形，防止混凝土開裂，在桁架的中部增設(shè)4根16的型鋼，間距1.0M，以加強(qiáng)跨中的橫向分布剛度。見圖七。3.3.3預(yù)拱度設(shè)置根據(jù)支架實(shí)際情況和預(yù)壓成果，預(yù)拱度設(shè)置分為6M和14M跨兩部分，

17、考慮不可預(yù)料的因素及箱梁的外形美觀，將預(yù)拱值提高35mm，跨中最大值設(shè)置為25MM。并按拋物線分配，見圖12： 沉降觀測結(jié)果 表1觀測點(diǎn)編號荷重0荷重80%沉降量卸載后非彈性變形彈性變形觀測值觀測值觀測值0左12.78212.778412.78022中12.87212.868412.87113右12.97112.967412.967400.25L左12.70512.6852012.701416中12.78612.7662012.781515右12.89912.8801912.8936130.5L左12.63312.6102312.628518中12.73912.7083112.731823右1

18、2.83712.8162112.8325160.75L左12.53312.5181512.530312中12.62312.6081512.624015右12.73512.7201512.730510L左12.44712.442511.44705中12.53712.530712.53434右12.64012.635512.63732L+3米左12.40112.399212.40011中12.49612.492412.49422右12.59312.587612.591243.4混凝土的澆注3.4.1混凝土的澆注順序現(xiàn)澆箱梁分段施工，每段分兩次澆注。為有利于支架的受力、減小支架變形，每段混凝土澆注順

19、序?yàn)椋嚎v向從每段的起點(diǎn)向終點(diǎn)澆注；橫向從起始跨的中間腹板和底板向兩側(cè)對稱澆注。3.4.2沉降觀測結(jié)果分析 在混凝土澆注過程中，觀測支架變形，測量成果見表2?？梢钥闯隹缰凶畲蟪两盗繛?2mm，小于預(yù)拱值3mm，橫向不均勻沉降最大為3mm。從拆模后的箱梁底板外觀看，線形順暢、美觀，達(dá)到預(yù)期要求。按預(yù)拱值25mm設(shè)置正確、可靠。 支架變形觀測成果 表2觀測點(diǎn)編號澆筑一次砼前第一次砼澆筑后沉降量（）第二次砼澆筑前第二次砼澆筑后沉降量（）最終沉降量（）觀測值觀測值觀測值觀測值0.25L左136921368661368613678814中135941358771358013571916右135071350

20、1613498134908140.5L左1378213774813774137631119中13694136841013682136711121右135961358610135841357212220.75L左1386013855513854138441015中134411343561343513427814右1365913655413656136451115L左13726137233137231372036中13689136872136881368446右137111370921371013707354.體會4.1主要優(yōu)點(diǎn)利用鋼管樁和貝雷片做現(xiàn)澆支架，直接利用既有承臺作為支架的支撐基礎(chǔ)，不需

21、處理地基，避免地基沉降帶來的影響，節(jié)約了投資，提高了材料的回收利用率。將主要受力構(gòu)件加工成大塊，用機(jī)械吊裝，提高了機(jī)械化作業(yè)程度和工效，節(jié)省了時間。整體落架法拆除桁架，不僅減少了高空作業(yè)量，保障了施工安全，而且提高了工效。直接利用固定在貝雷片主弦桿上的方木代替鋼管調(diào)整高程，節(jié)約了投入。4.2存在的不足和需進(jìn)一步改進(jìn)的問題鋼管的接長和拆除，全部采用電焊、氣割，現(xiàn)場焊接工作量大，對操作工人的要求高，且對鋼管質(zhì)量有損傷。改進(jìn)措施：將鋼管分段加工成型，根據(jù)需要組拼。由于貝雷片采用非標(biāo)準(zhǔn)間距布設(shè)，橫向及底水平連接主要采用了焊接方式，現(xiàn)場焊接量大，工效低。改進(jìn)措施：改焊接為栓接。參考文獻(xiàn)：劉宗祿.流亭立交

22、橋連續(xù)箱梁施工技術(shù)總結(jié).鐵道建設(shè)優(yōu)秀論文選編.中國鐵道建筑總公司1991-1993.黃紹金.劉陌生.裝配式公路鋼橋多用途使用手冊.張克治.后張預(yù)應(yīng)力連續(xù)箱梁施工.京福高速公路論文集.12improve, security prevention capacity obviously enhanced, security hidden and security accident obviously reduced, effective guarantees information health development. XX Education Centre regularly carry out

23、 day-to-day network security monitoring information and equipment. By the appropriate technical staff, XX network engine room maintenance staff on site management and maintenance on a regular basis, scheduled viewing of networks, systems, databases and associated equipment operating conditions, and

24、make a record. Computer lab maintenance managers regularly run a variety of devices in the school information system parameters, server systems and various data backup, so that there was a hardware failure in a system crash can resume quickly and efficiently. Computer lab maintenance managers establ

25、ish a network antivirus system, Avira Virus system on a regular basis, and anti-virus software security assessment, time to upgrade. Computer lab maintenance management for all equipment in the room a regular dust, replace the old label. Regularly host servers, network switches, core routing, firewa

26、lls, hardware maintenance, such as equipment failure, should be processed in a timely manner in order to ensure safe and reliable operation of the system. In XX city information and equipment was established within the Centre, educational metropolitan area network center machine room XX. Servers and

27、 data stores and applications to set up in XX City metropolitan area network center machine room. WindowsServer2003, windowsServer2008, windowsServer2012, Linux, the operating system, the database for SQL Server2008, Office software, such as Microsoft Office software. Schools (units) of computer, in

28、formation system security products for domestic products, including the use of 360 and kingsoft Internet security software. XX education metropolitan area network used by the server for HP, firewall and information security product for Huawei and Cisco products. In their daily work, to publicize rel

29、ated knowledge and information security considerations. Enhanced global awareness of network and information security, and strive to achieve network everyone knows security and virus before the guard, to improve network and information security, ensure that the XX education system network and inform

30、ation system security. Tracking reporting system requires all parties to strengthen collaboration, work closely with emergency safety plan developed XX education metropolitan area network, regularly carry out emergency drills, and carried out special funds every year to protect the security of infor

31、mation. Annual 2-3 professional training for network managers in the city, forming technology with a strong professional and technical team, school network managers on common network failures and be capable of solving security issues. Issues that cannot be resolved, timely forms of meetings, such as

32、 meetings, analysis, and solutions through a meeting, without rolling up the ability to solve problems, and feedback to superiors in writing departments to resolve. Through self-examination, we are well aware, relative lack of investment in education, facilities and equipment for further updates, ed

33、ucation development is still uneven, new education concepts need to be further enhanced to some extent and restricting the development of city education. We will take the opportunity of government supervision, to strive for the province education demonstration counties as a driving force, further in

34、crease input in education, efforts to promote thelong wing, and Li Wanfu, and Michael Jenkins, and Chen Jian, and Song and xiaochuanyun, 7 bit comrade participate in province backbone face-to-face or network learning, do each teaching points are has teachers participate in training, October 17, 2013

35、, issued XX city education information and equipment Center on requirements the teaching points school for good satellite ground station installation prepared of notification, requirements school related management personnel familiar XX province teaching points digital education resources full cover

36、 project construction management manual, Particularly with regard to installation preparation parts according to the point of XX province full coverage of digital educational resources in the project construction management manual . Devices are able to receive TV signals and IP data, the schools hav

37、e school training and school-based application to use good. Actively organize implementation of a division of a class, a teacher in one class activity. XX in XX city first to complete full registration of teachers working in this city, XX, Sun class rate of 54 per cent respectively, the forefront. I

38、n XX, a division of a class, a class a total ranked first in Division activities, was awarded the national ministerial one, 2 provincial second prize, third prize at the provincial level 3. Actively organize implementation of the e-learning space the work of everyone. At present, in the open space o

39、f public service platform of provincial educational resources teachers number 2444, 83 to the total number of teachers, student number is 6569 of the open space, the city's total students 18.31 to (junior high school students in 30 above, students not required), registration number to meet the r

40、equirements of teachers and students, in XX in first place. Five, information technology application capability as a means to boost teaching of teachers to use information, Education Bureau of XX title and modern educational technology teacher assessment levels linked to the examination; launched a provincial model school of modern education technology selection, advanced unit in education a year (individual) award. To expedite educa