1、安装模板和浇筑砼时，应注意保护钢筋，不得攀踩钢筋。2、钢筋的砼保护

1. When installing formwork and pouring concrete, care should be taken to protect the steel bars, and the steel bars must not be climbed. <br>2. The thickness of the reinforced concrete protective layer is generally not less than 50mm. The reinforcement pads shall not be omitted. <br>3. When removing the mold, avoid heavy prying and hard smashing to avoid damage to the concrete and steel formwork. <br>Fourth, the technical measures to ensure quality <br>1. Honeycomb and exposed ribs: due to the lack of template splicing, the concrete leaks cause honeycomb; vibration does not operate according to the process, causing the vibration to be compact and exposed. <br>2. The lack of edges and corners, the inaccurate mix ratio, uneven mixing or premature mold removal, and insufficient maintenance will cause damage to the concrete edges and corners. <br>3. Excessive deviation: The distance between the formwork support, clips and tie rods is too large or not firm; too high local concrete pouring or long vibration time will cause defects such as bulging, staggering and tilting of the concrete. <br>4. Displacement of inserted steel bars: The inserted iron is not firmly fixed, and the vibrating rod collides with the steel bars, causing the steel bars to move. <br>3. Backfilling engineering <br>The backfilling in this project uses mechanical backfilling. The frog-type ramming machine is used for ramming and filling. The parts where the frog-type ramming machine cannot ramming are manually rammed. <br>1. Materials and main machinery and equipment: <br>1.1 Soil: It is advisable to use the soil excavated in the foundation tank first, but it must not contain organic impurities, its particle size is not more than 50mm, and the moisture content should meet the regulations. <br>1.2 The main machines are: frog-type ramming machine, trolley, shovel (pointed and flat head), rubber hose, small wire and wooden folding ruler. <br>2. Operating conditions: <br>2.1 Before construction, the parameters such as the moisture control range of the fill soil, the thickness of the virtual paving, and the number of compaction passes should be reasonably determined according to the engineering characteristics, type of fill soil, density requirements, and construction conditions. <br>2.2 Before backfilling, the foundation, underground waterproof layer, protective layer, etc. should be inspected and accepted, and hidden inspection procedures should be completed. <br>2.3 Before construction, level signs should be made to control the height or thickness of the backfill. For example, on the slope of the foundation pit, horizontal prongs should be nailed every 3m; horizontal lines should be popped up indoors or on the side walls of the scattered water, or elevation control wooden piles should be nailed to the floor. <br>3. Operation process<br>3.1 Technological process: <br>foundation pit cleaning → soil quality inspection → layered soil laying and <br>rake leveling → ramming compaction → inspection compactness → trimming and leveling acceptance 3.2 The garbage and debris on the foundation pit should be cleaned up before filling. Check whether the quality of backfill soil is debris, whether the particle size meets the regulations, and whether the water content of backfill soil is within the control range; if the water content is too high, measures such as loosening, drying or even mixing with dry soil can be used; In case of low water content of backfill, measures such as pre-sprinkling and wetting may be used. Backfill soil should be paved in layers. The thickness of each layer of soil should be determined according to soil quality, compactness requirements and machine performance. The thickness of each layer of the general frog-type ramming machine is 200-250mm; the manual ramming is not more than 200mm. After each layer is paved, it is followed by raking. <br>3.3 Each layer of backfill is rammed at least three times. The ramming should be one ramming and half ramming, and the ramming and ramming are connected, line by line, and crosswise. <br>3.4 When the deep and shallow foundation pits (troughs) are connected, the deep foundation should be filled first; when the shallow foundation pits are filled to the same elevation, the shallow foundation will be filled together with the shallow foundation. If it is necessary to fill the ramming section by section, the junction should be filled with a ladder shape, and the aspect ratio of the ladder shape is generally 1: 2. The distance between the upper and lower layers is not less than 1.0m. Backfilling of foundation pits (grooves) should be performed simultaneously on opposite sides or sides. The elevations of the two sides of the foundation wall must not be too different, so as to avoid squeezing the wall, the longer pipe trench wall should adopt internal support measures, and then backfill the earth on the outside. In order to prevent the displacement of the centerline of the pipeline or damage to the pipeline when filling the center of the house and the trench, the soil should be filled on both sides of the pipe and rammed; In the case of pipelines, frog-type ramming machines can be used for tamping. At the wiper interface, around the anti-corrosion insulation layer or cable, fine particles should be backfilled. After tamping each layer of backfill, the ring cutter should be sampled according to the specifications to measure the mass density of the dry soil; after meeting the requirements, the next layer of soil should be spread. <br>3.5 Finishing and leveling: After the completion of the filling, the surface shall be leveled by wire drawing. Wherever the standard elevation is exceeded, it shall be shoveled in time according to the line; where the level is below the standard elevation, layered leveling shall be added.

1、安装模板和浇筑砼时，应注意保护钢筋，不得攀踩钢筋。<br>2、钢筋的砼保护层厚度一般不小于50mm。其钢筋垫块不得遗漏。<br>3、拆模时应避免重撬、硬砸，以免损伤砼和钢模板。<br>四、保证质量的技术措施<br>1、蜂窝、露筋：由于模板拼接不严，砼漏浆造成蜂窝；振捣不按工艺操作，造成振捣不密实而露筋。<br>2、缺棱、掉角，配合比不准，搅拌不均匀或拆模过早，养护不够，都会导致砼棱角损伤。<br>3、偏差过大：模板支撑、卡子、拉杆间距过大或不牢固；砼局部浇筑过高或振捣时间过长，都会造成砼胀肚、错台、倾斜等缺陷。<br>4、插筋钢筋位移：插铁固定不牢固，振捣棒碰撞钢筋，致使钢筋位移。<br>3、回填土工程<br>本工回填土采用机械回土，蛙式打夯机夯填，局部蛙式打夯机不能夯填部位由人工夯实。<br>1、材料及主要机具：<br> 1.1 土：宜优先利用基槽中挖出的土，但不得含有有机杂质，其粒径不大于50mm，含水率应符合规定。<br> 1.2 主要机具有：蛙式打夯机、手推车、铁锹(尖头与平头)、胶皮管、小线和木折尺等。<br>2、 作业条件：<br> 2.1 施工前应根据工程特点、填方土料种类、密实度要求、施工条件等，合理地确定填方土料含水率控制范围、虚铺厚度和压实遍数等参数。<br> 2.2 回填前应对基础、地下防水层、保护层等进行检查验收，并且要办好隐检手续。<br> 2.3 施工前，应做好水平标志，以控制回填土的高度或厚度。如在基坑边坡上，每隔3m钉上水平橛；室内和散水的边墙上弹上水平线或在地坪上钉上标高控制木桩。<br>3、操作工艺<br> 3.1 工艺流程：<br> 基坑清理→检验土质→分层铺土、耙平→夯打密实→检验密实度→修整找平验收<br> 3.2 填土前应将基坑上的垃圾、杂物清理干净。检验回填土的质量有无杂物，粒径是否符合规定，以及回填土的含水量是否在控制的范围内；如含水量偏高，可采用翻松、晾晒或均匀掺人干土等措施；如遇回填土的含水量偏低，可采用预先洒水润湿等措施。 回填土应分层铺摊。每层铺土厚度应根据土质、密实度要求和机具性能确定。一般蛙式打夯机每层铺上厚度为200～250mm；人工打夯不大于200mm。每层铺摊后，随之耙平。<br> 3.3 回填土每层至少夯打三遍。打夯应一夯压半夯，夯夯相接，行行相连，纵横交叉。<br> 3.4 深浅两基坑(槽)相连时，应先填夯深基础；填至浅基坑相同的标高时，再与浅基础一起填夯。如必须分段填夯时，交接处应填成阶梯形，梯形的高宽比一般为1：2。上下层错缝距离不小于1.Om。基坑(槽)回填应在相对两侧或四周同时进行。基础墙两侧标高不可相差太多，以免把墙挤歪，较长的管沟墙，应采用内部加支撑的措施，然后再在外侧回填土方。 凹填房心及管沟时，为防止管道中心线位移或损坏管道，应用人工先在管子两侧填土夯实；并应由管道两侧同时进行，直至管顶0.5m以上时，在不损坏管道的情况下，方可采用蛙式打夯机夯实。在抹带接口处，防腐绝缘层或电缆周围，应回填细粒料。回填土每层填土夯实后，应按规范规定进行环刀取样，测出干土的质量密度；达到要求后，再进行上一层的铺土。<br>3.5修整找平：填土全部完成后，应进行表面拉线找平，凡超过标准高程的地方，及时依线铲平；凡低于标准高程的地方，应补上分层找平。

1. When installing the formwork and pouring the concrete, pay attention to protect the reinforcement, and do not step on the reinforcement.<br>2. The thickness of concrete protective layer of reinforcement is generally not less than 50mm. The reinforcement cushion block shall not be omitted.<br>3. During formwork removal, heavy prying and hard smashing shall be avoided to avoid damage to concrete and steel formwork.<br>4、 Technical measures for quality assurance<br>1. Honeycomb and exposed reinforcement: honeycomb is caused due to loose splicing of formwork and leakage of concrete; vibration is not conducted according to the process, resulting in uncompacted vibration and exposed reinforcement.<br>2. Lack of edges and corners, inaccurate mix proportion, uneven mixing, early formwork removal and insufficient maintenance will lead to damage of concrete edges and corners.<br>3. Excessive deviation: the distance between formwork support, clip and tie rod is too large or not firm; the local pouring of concrete is too high or the vibrating time is too long, which will cause the defects of concrete bulging, misplacement and inclination.<br>4. Displacement of steel bar of joint bar: the iron bar is not fixed firmly, and the vibrator collides with the steel bar, resulting in displacement of the steel bar.<br>3. Backfill engineering<br>Mechanical backfilling is adopted for the backfill of the project, and frog rammer is used for tamping, and parts that cannot be tamped by frog rammer are tamped manually.<br>1. Materials and main machines and tools:<br>1.1 soil: the soil excavated from the foundation trench should be used preferentially, but it should not contain organic impurities, its particle size should not be greater than 50mm, and the water content should meet the requirements.<br>1.2 main machines are: frog rammer, trolley, shovel (pointed and flat head), rubber hose, small line and wooden folding ruler.<br>2. Operating conditions:<br>2.1 before construction, the water content control range, virtual paving thickness, compaction times and other parameters of fill soil shall be reasonably determined according to the project characteristics, fill soil type, compactness requirements, construction conditions, etc.<br>2.2 before backfilling, the foundation, underground waterproof layer, protective layer, etc. shall be inspected and accepted, and the hidden inspection procedures shall be completed.<br>2.3 before construction, horizontal signs shall be made to control the height or thickness of backfill. For example, on the side slope of the foundation pit, the horizontal pegs shall be nailed every 3M; the horizontal lines shall be marked on the side walls of indoor and apron or the elevation control stakes shall be nailed on the floor.<br>3. Operation process<br>3.1 process flow:<br>Foundation pit cleaning → soil quality inspection → layered soil laying and raking → compaction → compactness inspection → trimming and leveling acceptance<br>3.2 before filling, the garbage and sundries on the foundation pit shall be cleaned. Check whether there are sundries in the quality of the backfill, whether the particle size meets the requirements, and whether the moisture content of the backfill is within the control range; if the moisture content is too high, measures such as scarifying, airing or even mixing with dry soil can be adopted; if the moisture content of the backfill is too low, measures such as watering in advance can be adopted. The backfill shall be spread in layers. The thickness of each layer shall be determined according to the soil quality, compactness requirements and the performance of machines and tools. Generally, the laying thickness of each layer of frog rammer is 200-250mm; the manual ramming is not more than 200mm. After each layer is spread, it will be raked.<br>3.3 each layer of backfill shall be rammed at least three times. The ramming shall be one ramming and half ramming. The ramming shall be connected with each other, the lines shall be connected, and the vertical and horizontal shall be crossed.<br>3.4 when the deep and shallow foundation pits (grooves) are connected, the deep foundation shall be filled and compacted first; when the shallow foundation pit is filled to the same elevation, it shall be filled and compacted together with the shallow foundation. If it is necessary to tamp in sections, the joint shall be filled in a stepped shape, and the height width ratio of the trapezoid is generally 1:2. The staggered distance between the upper and lower layers shall not be less than 1.om. The backfilling of foundation pit (groove) shall be carried out at the same time on opposite sides or around. The elevation of both sides of the foundation wall shall not differ too much, so as to prevent the wall from being squeezed out. For the long pipe trench wall, the measures of internal support shall be adopted, and then the earthwork shall be backfilled outside. In order to prevent the displacement of the center line of the pipeline or damage to the pipeline, the filling and compaction shall be carried out manually on both sides of the pipe first; and it shall be carried out simultaneously on both sides of the pipe until the pipe top is more than 0.5m, and the frog rammer can be used for compaction without damage to the pipeline. At the joint of plastering tape, around the anticorrosive insulating layer or cable, fine aggregate shall be backfilled. After each layer of backfill is tamped, the ring cutter sampling shall be carried out according to the specifications to measure the mass density of dry soil; after meeting the requirements, the upper layer of soil shall be paved.<br>3.5 trimming and leveling: after the filling is completed, the surface shall be leveled by pulling line. Where the elevation exceeds the standard elevation, the surface shall be leveled according to the line in time; where the elevation is lower than the standard elevation, the layered leveling shall be added.<br>