基坑支护及降水

1、1、Project Description工程概述费列罗食品(杭州)有限公司项目位于杭州经济技术开发区江东新区高技术产业区域内，新建总建筑面积约46615，其中地下建筑面积约535，主要为生产车间贯穿东西的地下通道：基底埋深为3.6m（相对±0.000为-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、地质概况Geological condition2.1地形地貌：本场地地貌属冲海积平原地貌单元，场地地形平坦，大部分为耕地，地面高程多在4.8-5.2米左右，局部分布有条带状积水沟，沟深约在0.5-1米左右。场地南北两侧分别有江东一路、

3、江东二路通过，西侧有新建的青西四路通过。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岩土层的构成及特征：根据本阶段勘探孔揭露的地层情况，场区上部为新近堆积的耕土、冲海相沉积的粉、砂土层，中部为海相沉积的粉土层及陆相沉积的粘土层、砂砾石层。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：场区地处钱塘江南岸，属钱塘江流域，拟建场地周边水系比较发育：根据地下水赋存条件、水力特征及岩土的水理性质，场地勘探深度范围内地下水主要为第四系松散岩类孔隙水，第四系松散岩类孔隙水又可分为孔隙潜水和孔隙承压水。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、初步设计支护及降水形式：双轴水泥搅拌桩+挂网喷浆的基坑支护和轻型井点降水系统组成。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、双轴水泥搅拌桩double axis cement mixed piling施工工艺（见下表）construction process (see below diagram)施工技术措施construction technical measurements 挖沟槽：沟槽开挖深度1.52m，宽度大于设计搅拌桩挡土墙宽度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.布设桩位:按设计要求使

9、用经纬仪测放各围护桩轴线及桩中心位置，各桩点采用固定标志确定桩中心位置，桩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.桩位复核check of pile location测量放样setout开挖沟槽e

10、xcavation ditch桩机就位locate piling machine配制浆液prepare the slurry预搅下沉pre-mix喷浆搅拌提升mixing and shot重复搅拌下沉re-mix重复搅拌提升pull out桩机移位move of machiince施工工艺流程construction diagram桩机就位：为了保证搅拌桩的垂直度，要注意起吊设备机架的平整度及导向架的垂直度，搅拌桩的垂直度偏差不得超过0.5%。定位要准确，保持垂直度，确保壁状加固体的连续性。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.预搅下沉：在输浆胶管与集料斗、灰浆泵同深层搅拌机连通及其他准备工作做好后，开动电机，启动搅拌机，

12、以0.5-0.75m/min的速度，沿导向边旋切土边下沉，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.制备浆液:搅拌机预搅下沉时，后台按水灰比0.5拌制水泥浆，配制浆液要严格控制用水量，拌合时间不得少于3min，制备好的浆液不得离析，停置时间不得超过2小时，待压浆前将浆液过筛后倒入集料斗中。泵送浆液前管路应保持潮湿，以利输浆。拌制浆液的罐数、水泥的用量和泵送时间由专人统计记录。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.喷浆搅拌提升：当搅拌机下沉到设计深度后，将搅拌机提升200mm，开动灰浆泵，把水泥浆压入土层中，为了保证桩端施工质量，当浆液到达出浆口后，原地喷浆不少于30s，使浆液完全到达桩端，然后以0.3-0.5m/min的均匀速度，边提升、边喷浆、边搅拌，使水泥与土体充分拌和，直至地面，送浆压力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.重复搅拌下沉、喷浆搅拌提升：为使土体与水泥浆液搅拌均匀，用同样方法，进行二次下沉、喷浆、搅拌、提升，将剩余浆液全部送入孔内。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.桩与桩的搭接时间

19、不应大于12小时，如特殊原因超过上述时间，应对最后一根桩行进行空钻，留出榫头以待下一批搭接。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挂网喷浆shotcrete with wire mesha.结合土方开挖，及时布置好土钉位置，并分层打设好土钉。To fit the excavation, the s

20、oil bolt location shall be marked and bolted in time.b.打设土钉要按设计角度及深度，发现异常要及时和有关部门联系采取有效措施。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.在土方挖至标高后，随即安排人员投入修坡、整坡，并用振动平板进行粗振平。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，在此基础上再铺设钢筋网片。Welding of12 main-rebar, fix wire mesh onto it.e.在浇设砼之前，要垫好保护层(3cm)。prepare the spacer for concrete cover before the shotcrete.f.喷射C20砼，厚度

22、5cm。shot out the C20 concrete, with thickness of 5cm.4.3 轻型井点降水small sized well pit water lower-down system（1）施工工艺construction process测放管线、泵站位置Setout the pipe line, location of pump铺设管线Distribution of pipe lines水力冲孔、下井点管Flashing holes, locate the vacuum pipe灌砂滤层Fill in filter sand layer粘土封孔、夯实Close

23、borehole with clay and compact井点管与总管接通Connection of vacuum pipe to main pipe水箱灌水Fill water into water-tank开机试运转Commissioning for the system按业主开机令开机抽排Start the system according to instruction按业主停机令停止抽排、拆机Stop/ dismantle according to instruction （2）施工技术Construction technique测量放样：根据土建单位测放的轴线及基坑上口开挖边线，测

24、放井点集水总管铺设线路、井点管及抽吸机泵等的位置。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.井点管成孔：采用.5潜水泵通过专用喷枪冲孔器进行水力冲孔，孔深要比井管埋置长度超深0.50m，孔径0.30，冲孔深度应比滤管底深0.50m左右，以保证井点管周围及底部有足够的滤层。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.下插井点管：井点管包扎滤网前先将管内的泥、砂等冲洗干净，滤网的层数和目数要根据土质情况选配，既要有一定的空隙率，又不能让砂土进入井点管。下插井点管用人工插放即可。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.灌砂滤层：下插井点管前先将土孔底部超深部分的砂滤层灌好，下插井管后将井管控制在土孔的中间，使井点管周围砂垫层的厚度一致。砂滤层保持沿井点管周围水平上升，以防在灌砂滤层的过程中将井点管挤到土孔的一边，影响井管的渗透效果，砂滤层灌至距地面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、夯实：地面以下0.50m范围内的土孔必须用

29、粘土回填并夯实，不让其跑气，试运行后及正常开机运行期间要经常检查、修复，保证闭气。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.集水总管铺设：集水总管的线路应沿基坑平台上肩口内0.50m处布置，高程基本与水泵轴线平行，这样机械效率高、磨损小。直线

30、段采用硬质铁皮管，拐弯处采用橡胶管，法兰接头间垫橡胶止水垫片。做到管线水平、顺直，接头牢固、不跑气、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.井点管与集水总管的联接：采用胶管联接，12#铁丝绑扎。The connection between vacuum pipe and main pipe: use hose to make the conne

32、ction and tighten by 12# steel wire.运行期巡查：运行期间必须确保每台机组日夜不间断地有效抽排，一旦有一台机组停抽，则整个降水工程将前功尽弃。为此，每天必须定时检查。Regular check: to ensure that all pump is working continuously, the daily check shall be made to avoid any pump out of service.基坑坡面保护:沿基坑上口外0.50m左右开挖一条小截水沟，以拦截平台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. 成型示意图如右侧所示：the finished shape shall refer to diagram (right side)5、基坑开挖过程中的安全监测saf

34、ety monitor and control沉降、位移监测:基坑开挖及地下室施工过程中，为了确保基坑万无一失，还必须采取有效的监测手段，为此，我们在基坑周围布置：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米设一位移观测点。Al

35、ong the ring beam, the monitor point to be set for each 5m.对周边道路每隔10m布设一个沉降监测点。Along the surrounding roads, the monitor points to be set for each 10m.临近建筑物设置沉降观测点。The observation point for the nearby building to be set up.监测的步骤：Procedure of monitor:1 监测点埋设相应标志，并请挖土单位注意在挖土过程中加以保护。To provide a visible

36、 mark at the monitor point, it shall be protected during the excavation.2 平位移、沉降、地下水位拟每二天观测一次，当开挖速度加快或开挖至设计深度时，加密观测间隔，必要时每天进行一次。量测周期：基坑土方开挖至地下室侧壁回填。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 监测控制要求：requirement for this observation: 支护桩：水平位移速度不超过3.0mm/d，位移总量小于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.周围道路及建筑物沉降速度不超过2.0mm/d，累计沉降量20mm，房屋差异沉降不超过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