管井降水施工方案设计.doc

word管井降水施工方案The construction scheme of tube well dewatering -柬埔寨安达都会广场项目 -VCLP PROJECT CAMBODIA编 制：piled:_审 批：Verified:_批 准：Approved:_日期：Date:_安达广场基坑降水施工方案Construction Scheme for Foundation Pit Drawdown of VATTANAC Park一、降水设计方案I. Drawdown design scheme、设计参数1.1. Design data本工程降水井采用直径300mm波纹管滤管，管井共20根井深22米，井口外露500mm。300mm corrugated filter pipe is adopted as the drawdown well and there are total 20 wells of 22m deep each. The wellhead exposes by 500mm.、降水井平面布置1.2. Layout of drawdown well降水井布置详见降水管井平面布置图。The arrangement of drawdown well is shown on the layout of drawdown well.二、施工准备II. Construction preparation、测量放线2.1. Surveying and setting out测量放线依据现场测量控制点，标高采用水准仪，并根据井点布置图采用全站仪放线定位。放线经复核后报管理公司确认方可进展施工。The surveying and setting out shall be based on the field survey control points and optical level shall be used for measuring the elevation. In addition, the total station instrument shall be used for the setting out and positioning according to the layout of well points. Setting out shall be performed after re-recheck and being reported to the management pany for confirmation.、施工用电、用水配置2.2 Electricity and water for construction1、施工用电直接从配电房接入，50kVA能完全满足降水用电负荷。1. The electricity for construction shall be directly connected from the switchgear room, and 50kVA can fully meet the drawdown load requirements.2、依据用水设备和施工经验，需用水量10m3/h直径50mm管，就能满足施工用水。2. Depending on the water equipment and based on the construction experience, the pipe of diameter 50mm with a water flow rate of 10m3/h can meet the construction requirements.、打井机械与井点设备2.3. Well drilling rig and well point equipment打井机械可根据工期要求变更。井点设备是由井点管、连接收、排水主管与抽水设备等组成。具体如下:The well drilling rig may very according to the schedule requirement. The well point equipment consists of well point pipe, connecting pipe, drain header and pumping equipment. The details are as follows:机械设备表List of mechanical equipment序号S/N设备名称Equipment Name规格Size单位Unit数量Qty1钻机Drilling rigXY型XY Model台Set12潜水泵Submerged pump台Set20备520 (5 standby)3配电箱Power distribution box个Piece124泥浆泵Mud pumpDN15台Set15挖机Excavator200 Model台Set1、抽水设备的型号2.4. Model of pumping equipment本工程抽水设备采用潜水泵，功率为、流量为58m3/h。口径为25mm。Submersible pump is used as pumping equipment, for which the power is 1.11.5kw, the flow rate is 58m3/h, and the diameter is 25mm.主要材料用量表List of main material consumption序号S/N材料名称Material name规格Size单位Unit数量Qty1波纹管Corrugated pipe300m4402滤料Filter material35mmt803水管Water pipem15004电缆Cablem1500、人员的组织2.5. Organization of personnel1、降水组织机构1. Drawdown organization 项目经理X庆科 ：088 432 1871现场经理田书峰 ：097 876 1875技术负责王春阳 ：097 476 8583降水班组钻井班组水电团队现场安全测量班组Project managerLiu Qing Ketel：088 432 1871Site managerTian Shu Fengtel：097 876 1875Technical representativeWang Chun Yangtel：097 476 8583Water&electricity teamDrawdown teamDrilling teamSite safetySurvey team三、施工工艺III. Construction technology降水井施工工艺流程The work flow of drawdown well construction放线定井位钻机就位钻井换浆吊放井管填滤料粘土封井洗井安装水泵、架设电缆铺设排水总管与沉砂池抽降水位观测封井Setting out positioning of well drilling rig well drilling mud fluid displacement lifting of well pipe filter material filling shut-in well with clay well flushing installing water pump and cable lay drain header and sedimentation tank drawdown by pumping optical level observation well shut-in1、测量定位1. Survey and positioning按施工图放出井的中心点。井位应设立显著标志，必要时用钢纤打入地面以下300mm，并灌石灰粉作标记。Mark out the center point of the well according to the construction drawing. A clear district sign shall be erected at the well position and a steel rod shall be driven by 300mm under the ground if necessary. In addition, lime powder shall be poured as marker. 2、钻孔定位2. Location of drill hole以定好的井位点为中心，500mm为直径作圆，向下开作为井口。深度以见原状土为准，确认无地下管线与地下构筑物后放护筒，护筒外侧填粘土封隔好表层杂填土，以防钻井冲洗液漏失。Taking the well location as the center, make a circle of diameter 500mm and cut a 0.4m opening downward. The depth shall be such that reaching the undisturbed soil. The retaining cylinder shall be laid after confirming there is no underground pipeline and structure. The outside of retaining cylinder shall be filled with clay to isolate the miscellaneous fill at the surface layer, so as to prevent the leakage of drilling fluid.3、桩机就位3. Pile driver positioning桩机就位时需用水准仪找平，做到稳固、周正、水平，以保证钻进过程中的钻机稳定。起落钻塔必须平稳、准确。钻机就位偏差应小于10mm，钻塔垂直度偏差应小于1%。For positioning of pile driver, optical level shall be used for leveling. It shall be stable,regular and horizontal, so as to ensure the stability of the drilling rig in the drilling process. The lifting and lowering of drilling tower must be stable and accurate. The deviation of drilling rig positioning should be less than 10mm and the verticality deviation of the drilling tower shall be less than 1%.4、造浆：4. Mud making:根据地层情况采用正循环钻方法成孔，一般采用地层自造浆护壁。当遇到砂层时，采用膨润土保持泥浆比重为1.1-1.15 g/cm3造浆护壁成孔。地层土质松散时，孔内泥浆应高于地面。According to the stratum layer, normal circulation drilling method shall be used for bore forming. Normally, the native mud is used for wall retaining. When sand layer is encountered, bentonite shall be used for mud (keeping the .) making and bore forming. When the soil is loose, the mud inside the bore shall be higher than the ground. 5、钻井5. Drilling钻进过程中要随时观察泥浆的流损变化，水的补充要泥浆的流损情况与时调整，一般应保持泥浆液面不低于井口下1米，当钻遇砂层，泥浆大量流失时，应加大补水量，并投入适量的膨润土形成一定粘度的泥浆以控制冲洗液漏失，防止塌孔事故。在以粘土为主的地层中钻井时，由于钻井自造浆较稠，钻进效率低，此时可排走一局部泥浆，补充清水，调整泥浆密度到适宜状态。钻进中发现塌孔、斜孔时应与时处理。缩孔时应经常提动钻具修扩孔壁，每次冲击时间不宜过长，防止卡钻。In the process of drilling, attention shall be always paid to the flowing loss of mud. The water makeup and mud flowing loss shall be timely adjusted. In general, the mud shall be kept at a level not lower than the wellhead by 1m. When sand layer is encountered and great amount of mud flows off, great amount of water shall be made up and proper amount of bentonite shall be put in to establish the mud of a certain viscosity, control the leakage of flushing fluid and prevent the bore collapse accident. When drilling in the stratum that is mainly formed by clay, because native slurry of the well is thick and the efficiency of drilling is low, in this case some mud can be discharged and clean water shall replenished to adjust the mud density to a proper state. Bore collapse and inclination during drilling shall be timely treated. In case of shrinkage cavity, the drilling tool shall be frequently lifted up for repairing and expanding the bore wall. The time of each percussion shall not be too long, so as to prevent jamming.6、换浆6. Mud fluid displacement钻孔至设计深度后一般应大于设计深度的，将钻头提高左右并加清水稀释，直到泥浆密度接近，粘度为1820s。现场观察一般以换浆后泥浆不染手为准。替浆过程中，应按排泥浆的清运或排放工作。After drilling to the design depth (normally deeper than the design depth by 0.5m 1.0m), the drilling bit shall be uplifted by about 0.5m and clean water shall be added for dilution till the density of mud reaches 1.05g/cm3 and the viscosity is 18 20s. For field observation, the criteria is that the mud does not adhere to hands after displacement. During displacement, mud removal or discharge shall be arranged. 7、下管7. Pipe placement、检查井管有无残缺、断裂与弯曲情况。Check whether the well pipe is damaged, broken and bent.、在波纹管外侧钻孔，孔径不小于20mm并在波纹管外包60目滤网不少于2层。Drill bores outside the corrugated pipe. The bore diameter shall be not less than 20mm, and the outside of the corrugated pipe shall be wrapped with 60-mesh strainer by not less than 2 courses.、使井管居于井孔正中，防止倾斜，并固定。Put the well pipe at the center of the well bore, avoid inclination and fix it.、下降第二节井管时，注意连接的公母接口，动作要轻缓，不能猛降猛放。When placing the second section of the well pipe, attention should be paid to the connection of the male and female interfaces. While doing the job, the action shall be light and slow, avoiding sudden placement.、井管安放应力求垂直并位于井孔中间；管顶部比自然地面高500mm左右。井管过滤局部应放置在含水层适当的X围内。Well pipe placement should be vertical and located in the middle of the well as far as possible; the pipe top shall be higher than the natural ground by about 500mm. The filter section of the well pipe should be placed in the proper range of the aquifer.8、填料8. Filling material、安装完井管后，在无砂滤水井管外侧与井壁之间填砾料。After installing the well pipe, gravel material shall be filled between the outer wall of the filter-free pipe and the well wall.、砾料应缓慢填入，防止冲歪井管，一次不可填入过多。接近井口处，用粘土封严，以防地面水、雨水流入。The gravel material should be slowly filled to prevent deflection of the well pipe due to flushing. The filling should not be too mush in one time. When it is near the wellhead, clay shall be used for shut-in, so as to prevent the surface water and rain water from in-flowing.、井管下入后，与时在井管与土壁间填充砂砾填料。粒径应大于滤网的孔径，一般为38mm的细砾石。砂砾滤料必须符合级配要求，将设计砂砾上、下限以外的颗粒筛除，合格率要大于90%，杂质含量不大于3%；填料要一次连续完成。After placing the well pipe, timely fill sand and gravel between the well pipe and the soil wall. The particle size of gravel should be larger than the filter mesh diameter, and it is generally 3 to 8mm fine gravel. Gravel filter material must meet the gradation requirements. The particles larger than the upper limit or smaller than the lower limit of the design gravel size shall be screened off. The rate of conformity shall be higher than 90% and the inclusion content shall not be more than 3%. Filling shall be pleted in one time continuously.9、洗井9. Well flushing成井后，用污水泵反复进展恢复性抽洗。洗井应在成井4小时内进展，以免时间过长，影响渗水效果。洗井后可进展试验性抽水，确定单井出水量与水位降低能否满足设计要求。After the well is formed, the sewage pump shall be used to repeatedly perform restorative pumping and flushing. Well flushing shall be performed within 4h after the well is formed, so as to avoid being left aside too long and affecting the seepage effect. After the well flushing, test pumping shall be performed to determine whether the discharge of single well and the lowering of optical level can meet the design requirements.10、安装抽水控制线路10. Installation of pumping control pipeline潜水泵在安装前，应对水泵本身和控制系统作一次全面细致的检查。检验电动机的旋转方向，各部位螺栓是否拧紧，润滑油是否加足，电缆接头的封口有无松动，电缆线有无破坏折断等情况，然后在地面上转35min，如无问题，始可放入井中使用。深井内安设潜水电泵，可用绳索吊入滤水层部位，上部应与井管口固定。潜水电动机、电缆与接头应有可靠的绝缘，每台泵应配置一个控制开关。主电源线路沿深井排水管路设置。安装完毕应进展试抽水，满足要求后始转入正常工作。Before installing the submersible pump, the pump itself and the control system shall be subject to a prehensive and detailed inspection. The following checks shall be made, such as the rotation direction of motor, whether the bolts at various places are tightened, whether lubricant is fully added, whether the cable connection seal is loose, whether the cables are damaged or broken, etc. After the checks, run the pump on the ground for 35min. It can be put into the well only if it is in good condition. For installing submersible pump inside a deep well, the pump may be lifted to filtration bed level with ropes and the pump top shall be fixed to the well head. The submersible motor, cable and joint shall be provided with reliable insulation and each pump shall be equipped with a control switch. The main power supply line shall be arranged along the drainage pipeline. After installation, trial pumping shall be performed and it shall be transferred to normal operation after satisfying the requirements.四、降水过程的控制IV. Control of the drawdown process1、在正式降水前应作抽水试验，以验证方案的可行性，根据抽水试验结果选择泵的扬程流量，基坑开挖前至停止抽水时止，每天对地下水位进展观测记录，调整抽水速度与抽水量。1. Pumping test shall be performed before drawdown to validate the feasibility of the scheme. Select the head and flow rate of the pump according to the pumping test. Monitor and record the groundoptical level before the excavation of foundation pit till the stop of pumping every day. Adjust the pumping speed and amount of water being pumped out.2、在基坑开挖过程中，应随时观测基坑侧壁、基坑底的渗水现象，并查明原因，与时采取施工措施，并检查基坑外管网有无渗漏。2. During the excavation of foundation pit, the seepage of the foundation side wall and foundation bottom shall be always monitored, for which the causes shall be identified and measures shall be taken. The pipe network outside the foundation pit shall be checked for seepage. 3、在抽水维护期间，根据单井出水量确定开、关水泵的时间间隔，委派专业人员24小时轮流值班，保证水泵正常运转与井内水位。现场准备多台备用水泵与零配件，以便与时更换或维修，注意保护井口，防止杂物掉入井内。3. During the pumping maintenance period, assign professional workers for 24h work on shifts, so as to determine the time for the startup and shutdown of water pump according to the water output of a single well and ensure the normal operation of the pump and the optical level in the well. Many spare pumps and spare parts shall be prepared on site for a timely replacement or repair. Pay attention to protect the wellhead and prevent debris from falling into the well.4、发现基坑出水、涌砂，应立即查明原因，组织处理。4. If water flowing out or boiling of sand is found in the foundation pit, the causes shall be immediately identified for settlement.5、降水开始时间为：基坑土方开挖前不少于10天。5. The beginning time of drawdown is: no less than 10 days before the excavation of foundation pit.6、降水时间持续：上部结构的自重大于地下水产生的浮力后方可停止降水。6. Drawdown duration: the drawdown may be stopped only when the dead weight of the superstructure is greater than the buoyancy generated by groundwater.五、降水管网布设V. Laying of drawdown pipe network1、降水用电缆应延基坑边布设，并在坑内降水井相对应的位置设置配电箱，电缆借助临近的支撑架设到坑边，并采用绝缘套管悬挂在坑边的护栏上。电缆布设和电箱布置详见降水电缆布置图。1. The cable for drawdown should be laid along the foundation pit, and the distribution box shall be set up at the corresponding location of the drawdown well in the pit. The cable use the nearest strutting structure to the side of pit and then it should be hung on the guardrail on the side of the pit with the insulating sleeve. The arrangement of cables and electric boxes are detailed in the layout of drawdown cables.2、降水用输水管线采用PVC排水管和沉砂池相结合的方法。地下水通过井水泵经排水管抽至沉砂池沉砂后沉砂池采用成品水箱埋设在靠近城市管网接入口的下水道排出场外。2. The drainage pipeline for drawdown is in the form of PVC drainage pipeline plus sedimentation tank. The ground water is pumped to the sedimentation tank (the sedimentation tank is a water tank embedded in the sewage near the municipal pipeline connection interface) by the well pump through the drainage pipe, and then discharged to the outside.六、降水工程质量保证措施VI. Measures for quality assurance of drawdown works、降水管理6.1. Drawdown management1、根据水位观测情况，控制降水井排水时间和时间间隔。1. According to the observation of optical level, control the drainage time and time interval of drawdown well drainage.2、安排两班人员日夜值班，进展排水降水控制操作、水位观测和数据记录。2. Arrange two shifts on duty day and night to perform drainage and drawdown control and operation, optical level observation and data record.3、在基坑开挖过程中，须密切注意降水效果，做好降水工作。3. During the excavation of foundation pit, attention must be paid to the effect of drawdown. The drawdown work shall be properly per