基坑支護(hù)及降水

1、1、Project Description工程概述費(fèi)列羅食品(杭州)有限公司項(xiàng)目位于杭州經(jīng)濟(jì)技術(shù)開發(fā)區(qū)江東新區(qū)高技術(shù)產(chǎn)業(yè)區(qū)域內(nèi)，新建總建筑面積約46615，其中地下建筑面積約535，主要為生產(chǎn)車間貫穿東西的地下通道：基底埋深為3.6m（相對±0.000為-4.7）。The FERRERO FOOD (HANGZHOU) CO.,LTD Project is located in Hangzhou Economic & Technical development area (HEDA), the area for this new construction is 46615m2

2、, among them there are 535m2 basement works, which is went through the production shop from East to West, its about 3.6m underground (which is -4.7m referring to ±0.000 level)2、地質(zhì)概況Geological condition2.1地形地貌：本場地地貌屬?zèng)_海積平原地貌單元，場地地形平坦，大部分為耕地，地面高程多在4.8-5.2米左右，局部分布有條帶狀積水溝，溝深約在0.5-1米左右。場地南北兩側(cè)分別有江東一路、

3、江東二路通過，西側(cè)有新建的青西四路通過。The ground surface status: this area is a part of an Alluvial and coast plain, the surface is flat, most are cultivated land, the floor level is between 4.8 and 5.2m, there is also local strip shaped water pound, the depth is various from 0.5 to 1m. there is JiangdongYilu at sout

4、h side and JiangdongErlu at North side, the QIngxiSilu is at west side.2.2巖土層的構(gòu)成及特征：根據(jù)本階段勘探孔揭露的地層情況，場區(qū)上部為新近堆積的耕土、沖海相沉積的粉、砂土層，中部為海相沉積的粉土層及陸相沉積的粘土層、砂礫石層。The character of soil and rock layer: according to geological borehole investigation, the upper part is cultivated soil and sedimentation of clay/san

5、d layer, the middle par is sediment of silt soil layer and continental sedimentation for clay layer and gravel layer.2.3地下水：場區(qū)地處錢塘江南岸，屬錢塘江流域，擬建場地周邊水系比較發(fā)育：根據(jù)地下水賦存條件、水力特征及巖土的水理性質(zhì)，場地勘探深度范圍內(nèi)地下水主要為第四系松散巖類孔隙水，第四系松散巖類孔隙水又可分為孔隙潛水和孔隙承壓水。Underground water: the construction field is located at the south bank o

6、f Qiantangjiang, it is part of qiangtangjiang watershed, the water system is well developed at the surrounding: refer to the underground water accumulation condition/ the water pressure condition and Geotechnical water character, the underground water at this investigation area is water accumulated

7、in the loose rock joints, and it includes water with and without pressure.3、初步設(shè)計(jì)支護(hù)及降水形式：雙軸水泥攪拌樁+掛網(wǎng)噴漿的基坑支護(hù)和輕型井點(diǎn)降水系統(tǒng)組成。The support and lower-down water solution: cement mixed piling + shotcrete with mesh for foundation pit, and small sized well pit water lower-down system.4、施工方法construction method4.1

8、雙軸水泥攪拌樁double axis cement mixed piling施工工藝（見下表）construction process (see below diagram)施工技術(shù)措施construction technical measurements 挖溝槽：溝槽開挖深度1.52m，寬度大于設(shè)計(jì)攪拌樁擋土墻寬度0.5m。Ditch excavation: the depth for ditch excavation is 1.5m2m, the width should be 0.5m wider than the designed pile wall width.布設(shè)樁位:按設(shè)計(jì)要求使

9、用經(jīng)緯儀測放各圍護(hù)樁軸線及樁中心位置，各樁點(diǎn)采用固定標(biāo)志確定樁中心位置，樁位布置的偏差不得大于20mm。Arrangement of the pile location: according to the design, the pile location shall be setout with theodolite for its axis, the location shall be marked with fixed marker, the deviation shall not exceed 20mm.樁位復(fù)核check of pile location測量放樣setout開挖溝槽e

10、xcavation ditch樁機(jī)就位locate piling machine配制漿液prepare the slurry預(yù)攪下沉pre-mix噴漿攪拌提升mixing and shot重復(fù)攪拌下沉re-mix重復(fù)攪拌提升pull out樁機(jī)移位move of machiince施工工藝流程construction diagram樁機(jī)就位：為了保證攪拌樁的垂直度，要注意起吊設(shè)備機(jī)架的平整度及導(dǎo)向架的垂直度，攪拌樁的垂直度偏差不得超過0.5%。定位要準(zhǔn)確，保持垂直度，確保壁狀加固體的連續(xù)性。Locate piling machine: to ensure the verticality of

11、pile, the verticality of guide frame and the horizontality of lift frame, the verticality deviation shall not exceed 0.5%. the locating of equipment must be accurate, thus the verticality is secured, and the continued (underground)wall will be ensured.預(yù)攪下沉：在輸漿膠管與集料斗、灰漿泵同深層攪拌機(jī)連通及其他準(zhǔn)備工作做好后，開動(dòng)電機(jī)，啟動(dòng)攪拌機(jī)，

12、以0.5-0.75m/min的速度，沿導(dǎo)向邊旋切土邊下沉，直至加固深度。Pre-mix: after the preparation of supply hose and material collection bucket, the cement slurry pump and underground mixer is connected, shall start the motor, operate the mixer, with the speed of 0.50.75m/min, following the guide edge line, cut into soil downward

13、s, till the designed depth.制備漿液:攪拌機(jī)預(yù)攪下沉?xí)r，后臺(tái)按水灰比0.5拌制水泥漿，配制漿液要嚴(yán)格控制用水量，拌合時(shí)間不得少于3min，制備好的漿液不得離析，停置時(shí)間不得超過2小時(shí)，待壓漿前將漿液過篩后倒入集料斗中。泵送漿液前管路應(yīng)保持潮濕，以利輸漿。拌制漿液的罐數(shù)、水泥的用量和泵送時(shí)間由專人統(tǒng)計(jì)記錄。Prepare the slurry: while the mixer cut into the soil for premix, the cement slurry with a 0.5 ratio shall be prepared, the water dosa

14、ge must be strictly controlled, the mixing time shall not less than 3 minutes, the prepared cement slurry shall not segregate, the stored time shall not exceed 2 Hrs, it shall be put into the collection bucket before pumping. The hose after the pump shall be wetted out, it will smoothen the pumping

15、of slurry. There should be nominated person for the records of prepared slurry quantity (bucket), amount for use of cement, pumping time.噴漿攪拌提升：當(dāng)攪拌機(jī)下沉到設(shè)計(jì)深度后，將攪拌機(jī)提升200mm，開動(dòng)灰漿泵，把水泥漿壓入土層中，為了保證樁端施工質(zhì)量，當(dāng)漿液到達(dá)出漿口后，原地噴漿不少于30s，使?jié){液完全到達(dá)樁端，然后以0.3-0.5m/min的均勻速度，邊提升、邊噴漿、邊攪拌，使水泥與土體充分拌和，直至地面，送漿壓力0.4-0.6Mpa。Mixing an

16、d shot: while the mixer reached the designed depth, the mixer shall be pulled up for 200mm, thus the cement slurry pump shall be switched on, push the cement slurry into the soil layer, to ensure the quality of pile head construction, while the cement slurry reached the spreading point, the spreadin

17、g shall not less than 30 seconds in this point, after the cement slurry reached the end of pile, the mixer shall be pulled out with a speed of 0.30.5m/minute, the pulling of mixer/ spreading of slurry/ mixing the soil and slurry shall be made at the same time, until the mixer pulled out to the groun

18、d surface, the pumping pressure shall be 0.40.6Mpa.重復(fù)攪拌下沉、噴漿攪拌提升：為使土體與水泥漿液攪拌均勻，用同樣方法，進(jìn)行二次下沉、噴漿、攪拌、提升，將剩余漿液全部送入孔內(nèi)。Re-mix: to ensure an uniformed mix of the soil and cement slurry, the same method, shall be made twice, the left over cement slurry should be completely pumped into the pile hole.樁與樁的搭接時(shí)間

19、不應(yīng)大于12小時(shí)，如特殊原因超過上述時(shí)間，應(yīng)對最后一根樁行進(jìn)行空鉆，留出榫頭以待下一批搭接。The time for connection of piles shall not exceed 12 hrs, if the time exceeded, the last pile shall be continuously mixing, to reserve the connection for next overlap.4.2掛網(wǎng)噴漿shotcrete with wire mesha.結(jié)合土方開挖，及時(shí)布置好土釘位置，并分層打設(shè)好土釘。To fit the excavation, the s

20、oil bolt location shall be marked and bolted in time.b.打設(shè)土釘要按設(shè)計(jì)角度及深度，發(fā)現(xiàn)異常要及時(shí)和有關(guān)部門聯(lián)系采取有效措施。The bolting of soil bolt shall follow the designed inclination angle and depth, any un-normal conditions shall be reported in time to related department.c.在土方挖至標(biāo)高后，隨即安排人員投入修坡、整坡，并用振動(dòng)平板進(jìn)行粗振平。After the soil excav

21、ation reached designed level, labor shall be arranged to make the scaling/ slopping, and the flat vibrator shall be used for rough leveling.d.焊接12骨筋，在此基礎(chǔ)上再鋪設(shè)鋼筋網(wǎng)片。Welding of12 main-rebar, fix wire mesh onto it.e.在澆設(shè)砼之前，要墊好保護(hù)層(3cm)。prepare the spacer for concrete cover before the shotcrete.f.噴射C20砼，厚度

22、5cm。shot out the C20 concrete, with thickness of 5cm.4.3 輕型井點(diǎn)降水small sized well pit water lower-down system（1）施工工藝construction process測放管線、泵站位置Setout the pipe line, location of pump鋪設(shè)管線Distribution of pipe lines水力沖孔、下井點(diǎn)管Flashing holes, locate the vacuum pipe灌砂濾層Fill in filter sand layer粘土封孔、夯實(shí)Close

23、borehole with clay and compact井點(diǎn)管與總管接通Connection of vacuum pipe to main pipe水箱灌水Fill water into water-tank開機(jī)試運(yùn)轉(zhuǎn)Commissioning for the system按業(yè)主開機(jī)令開機(jī)抽排Start the system according to instruction按業(yè)主停機(jī)令停止抽排、拆機(jī)Stop/ dismantle according to instruction （2）施工技術(shù)Construction technique測量放樣：根據(jù)土建單位測放的軸線及基坑上口開挖邊線，測

24、放井點(diǎn)集水總管鋪設(shè)線路、井點(diǎn)管及抽吸機(jī)泵等的位置。Setout: refer to the axis line and excavation boundary line (setout by civil team), setout the plumbing line and location for pump and vacuum pipe hole.井點(diǎn)管成孔：采用.5潛水泵通過專用噴槍沖孔器進(jìn)行水力沖孔，孔深要比井管埋置長度超深0.50m，孔徑0.30，沖孔深度應(yīng)比濾管底深0.50m左右，以保證井點(diǎn)管周圍及底部有足夠的濾層。Borehole for the vacuum pipe: ado

25、pt the 7.5KW submersible pump and special water jet for borehole, the hole depth shall be 0.5m deeper than the pipe length and the filter surrounded shall be sufficient, the hole diameter shall not smaller than 0.3m.下插井點(diǎn)管：井點(diǎn)管包扎濾網(wǎng)前先將管內(nèi)的泥、砂等沖洗干凈，濾網(wǎng)的層數(shù)和目數(shù)要根據(jù)土質(zhì)情況選配，既要有一定的空隙率，又不能讓砂土進(jìn)入井點(diǎn)管。下插井點(diǎn)管用人工插放即可。Plu

26、g in the vacuum pipe: the pipe shall be flashed before closing by filter mesh, the layer and density of mesh shall be calculated according to local soil condition, there should be sufficient joint and the sand and soil shall not be able to get into the pipe. The pipe can be simply placed into the ho

27、le.灌砂濾層：下插井點(diǎn)管前先將土孔底部超深部分的砂濾層灌好，下插井管后將井管控制在土孔的中間，使井點(diǎn)管周圍砂墊層的厚度一致。砂濾層保持沿井點(diǎn)管周圍水平上升，以防在灌砂濾層的過程中將井點(diǎn)管擠到土孔的一邊，影響井管的滲透效果，砂濾層灌至距地面0.50m高程即可。Fill in the filter sand layer: the sand filter layer below the pipe shall be placed before placing of pipe. After the placing of pipe, the pipe shall be adjusted to fix i

28、nto middle of hole, thus the thickness of surrounding sand could be the same. The sand shall be filled uniformly to avoid the sand accumulated at one side of pipe, or the quality of water seepage will be affected. The sand fill can be stopped at 0.5m below the ground level.粘土封孔、夯實(shí)：地面以下0.50m范圍內(nèi)的土孔必須用

29、粘土回填并夯實(shí)，不讓其跑氣，試運(yùn)行后及正常開機(jī)運(yùn)行期間要經(jīng)常檢查、修復(fù)，保證閉氣。Closing of hole, compaction: the gap 0.5m below the ground, shall be closed by clay and compacted, to avoid the loose of vacuum. After the commission, regular check shall be made to ensure the vacuum.集水總管鋪設(shè)：集水總管的線路應(yīng)沿基坑平臺(tái)上肩口內(nèi)0.50m處布置，高程基本與水泵軸線平行，這樣機(jī)械效率高、磨損小。直線

30、段采用硬質(zhì)鐵皮管，拐彎處采用橡膠管，法蘭接頭間墊橡膠止水墊片。做到管線水平、順直，接頭牢固、不跑氣、不漏水。The water collection main pipe laying: the main pipe shall be installed 0.5m offset along the excavation pit. Its level shall be same to the water pipe pipeline, thus the efficiency of system is high. The straight part can be made with solid stee

31、l pipe , the bending can be connected with rubber hose. The rubber seal shall be used and the flange connection. The pipe installation shall be straight, smooth and horizontal, water and air tight.井點(diǎn)管與集水總管的聯(lián)接：采用膠管聯(lián)接，12#鐵絲綁扎。The connection between vacuum pipe and main pipe: use hose to make the conne

32、ction and tighten by 12# steel wire.運(yùn)行期巡查：運(yùn)行期間必須確保每臺(tái)機(jī)組日夜不間斷地有效抽排，一旦有一臺(tái)機(jī)組停抽，則整個(gè)降水工程將前功盡棄。為此，每天必須定時(shí)檢查。Regular check: to ensure that all pump is working continuously, the daily check shall be made to avoid any pump out of service.基坑坡面保護(hù):沿基坑上口外0.50m左右開挖一條小截水溝，以攔截平臺(tái)以上的雨水及其它水流不流入基坑。 The excavation pit slo

33、pe surface protection: a separation ditch 0.5m offset from the excavation pit shall be made at right and left side at the outside of excavation pit. To avoid the rain water or other water flow into the excavation pit. 成型示意圖如右側(cè)所示：the finished shape shall refer to diagram (right side)5、基坑開挖過程中的安全監(jiān)測saf

34、ety monitor and control沉降、位移監(jiān)測:基坑開挖及地下室施工過程中，為了確?；尤f無一失，還必須采取有效的監(jiān)測手段，為此，我們在基坑周圍布置：Settlement/movement monitor: During excavation for foundation and basement, to ensure safety for the excavation pit, it is necessary to adopt workable monitor measurements, thus we proceed following: 沿圈梁面每隔5米設(shè)一位移觀測點(diǎn)。Al

35、ong the ring beam, the monitor point to be set for each 5m.對周邊道路每隔10m布設(shè)一個(gè)沉降監(jiān)測點(diǎn)。Along the surrounding roads, the monitor points to be set for each 10m.臨近建筑物設(shè)置沉降觀測點(diǎn)。The observation point for the nearby building to be set up.監(jiān)測的步驟：Procedure of monitor:1 監(jiān)測點(diǎn)埋設(shè)相應(yīng)標(biāo)志，并請挖土單位注意在挖土過程中加以保護(hù)。To provide a visible

36、 mark at the monitor point, it shall be protected during the excavation.2 平位移、沉降、地下水位擬每二天觀測一次，當(dāng)開挖速度加快或開挖至設(shè)計(jì)深度時(shí)，加密觀測間隔，必要時(shí)每天進(jìn)行一次。量測周期：基坑土方開挖至地下室側(cè)壁回填。For each 3 days, the observation for horizontal movement/ settlement/ underground water level shall be made once, while the excavation reach the design

37、level or the excavation speed been accelerated, there should be more observation made, or it shall be once a day if necessary. The observation shall be proceeded from excavation start till the backfill up to basement side wall.3 監(jiān)測控制要求：requirement for this observation: 支護(hù)樁：水平位移速度不超過3.0mm/d，位移總量小于1挖深

38、。Support pile: the horizontal movement shall not exceed 3mm/day, the total movement shall less than 0.1% of the excavation depth.周圍道路及建筑物沉降速度不超過2.0mm/d，累計(jì)沉降量20mm，房屋差異沉降不超過2/1000。The settlement speed of surrounding road and building shall not exceed 2mm/day, total settlement shall not exceed 20mm, the uneven settlement for building