What are the procedures for building drainage culverts in Xiaoxigou, which is more than 2 square kilometers?

The construction organization design of slab culvert 1 is based on the design drawings of reinforced concrete slab culvert in J2 contract section of Nanyu Expressway of Sichuan Highway Survey and Design Institute, technical standards and specifications related to construction, actual situation on site and construction conditions of our company. 2 Project Overview This culvert is located at K 10+340, which is a pedestrian passage and drainage culvert. The inclined culvert of this culvert is under construction, which forms an angle of 60 with the line. The water inlet is trenched at 100m to connect with the original ditch, and the water outlet is trenched at 150m to connect with the original ditch. Nanchong bank crossed the water, Chongqing bank crossed the people, and the sidewalk board crossed the side ditch. See the following table 1 for the main engineering quantities. Geological conditions: According to the design data, the culvert foundation soil is mudstone, and its basic bearing capacity is 0=0.30MPa, which meets the requirement that the bearing capacity of culvert design foundation must be greater than or equal to 0.25Mpa. On-site transportation: The culvert site is close to the existing service road where the box culvert is located at K 10+403.58, and the materials needed for construction can be transported to the construction site by car using the longitudinal construction service road of subgrade. Construction water: the surface water around the culvert is rich, which can be used as construction water after inspection; Power consumption for construction: As the power consumption for the culvert construction is not large and the service time is not long, it is planned to use 10KW generator to generate electricity. Table 1 Description of foundation excavation of main engineering quantity unit table m3 excavation m3 hole body covers Class I reinforcement kgII 25 concrete m3 platform C20 concrete m3 foundation 7.5# mortar masonry m3 cushion 7.5# mortar masonry (pebbles) m3 hole cap 7.5# mortar masonry m3 wing wall and foundation 7.5# mortar masonry m3 waterproof wall and cushion 7.5# mortar tile (pebbles) m3 1 Cm thick felt support m2, roadway paving and stop 7.5# mortar tile (pebble) 165438 roadway cover plate crosses the ditch, roadway cover plate KGKGKGKGm3 culvert m3 is replaced by gravel/gravel m3 base, and gravel m3 foundation pit is backfilled with gravel m3φ300/. Φ Φ Φ 529 mm cast iron pipe m pedestrian step and mortar ditch 7.5# mortar slab (egg)/block stone/14.63. Construction scheme 3. 1 construction preparation 3. 1 survey lofting (1) On the premise of remeasuring the leveling points, the leveling points will be measured back and forth. (2) Before construction, check the elevation of the exit surface according to the design requirements, and determine the central axis of the culvert according to the structural size of the culvert. 3. 1.2 On-site investigation, carefully check whether there are structures, trees, etc. according to the design data and the determined culvert center line, combined with the actual terrain and geological conditions. If there is any influence on the construction within the construction scope, contact the relevant units in time to solve it. 3. 1.3 materials preparation The varieties and specifications of cement, sand, gravel, flaky, steel bars and other materials required for culvert construction should be selected according to the requirements of design and relevant construction specifications, and raw materials should be sampled and sent for inspection according to design and relevant specifications. Qualified raw materials are sent to the construction site by the material management personnel of the project department in stages according to the needs of the project progress. See attached table 1, 3. 1.4 for the main materials required for culvert construction. Construction personnel and management personnel and construction personnel required by machines and tools have been put in place, and all kinds of machines and tools have been equipped with good performance and in place. Labor and mechanical equipment required for culvert construction are shown in Schedule 2 and Schedule 3. 3. 1.5 Construction site layout According to the field investigation, the construction site at the culvert is narrow, which cannot meet the requirements of stacking materials and does not meet the conditions for building construction access roads. Considering that there is not much material needed for this culvert, it is planned to transport the required materials to the existing roadside near the construction site by car, and then transport them to the construction site by manpower. 3.2 Construction Scheme 3.2. 1 Foundation Pit Excavation The culvert foundation excavation is 2377m, 1440m, and the excavation depth is 4m. Therefore, excavators are used for excavation, and blasting excavation is carried out when necessary. See attached drawings for excavation dimensions. Observe the stability of slope at any time during excavation, and make original records. Due to the close proximity to paddy fields, after the foundation pit bottom reaches the design elevation, 30×30cm drainage ditch and 60×60cm ponding well are set around the foundation pit, so as to discharge the ponding in the foundation pit in time and ensure that the basement soil is not soaked by water. After the foundation pit is excavated to the elevation, the foundation bearing capacity test shall be carried out immediately and reported to the supervision engineer for inspection. If the geology and bearing capacity of the basement do not meet the design requirements, we will go to the site to study the treatment scheme together with the relevant personnel of the owner, design, supervision and construction unit. The excavation of spoil shall not hinder the future foundation pit and mortar masonry construction, and the distance from the toe of spoil pile to the top edge of foundation pit shall not be less than the excavation depth of foundation pit. 3.2.4 After the foundation pit of mortar masonry passes the inspection, the back cover and culvert foundation construction shall be carried out immediately to avoid the long-term exposure of the basement and reduce its bearing capacity. The stone should be roughly square, and the top and bottom should be roughly parallel. The thickness of stone is 200 ~ 300mm. The width and length of the stone should be 1 ~ 1.5 times and 1.5 ~ 3 times of the stone thickness, respectively. The sharp corners of the stone should be chiseled away. When laying in layers, the horizontal joint should be roughly horizontal, each joint should be staggered, and the staggered joint between two layers should not be less than 8 cm. The stones are staggered, the bite is dense, the mortar is full, and there are no holes in the joint filling. The thickness of 7.5# mortar rubble used for paving shall not be less than 150mm (ellipse and thin plate are not allowed). Face stones must be hand-chiseled, with smooth and angular surfaces. In order to ensure that the masonry size of the side wall and wing wall meets the design requirements, the frame with structural size made according to the design section size must be placed during masonry, and the flaky masonry must be strictly hung on the frame. In order to strengthen the connection between the foundation and the wall, when the foundation is laid to the top of the design elevation, stalagmites are left at the connection between the foundation and the wall to facilitate the connection. In order to make the exposed surface of culvert side wall and wing wall neat and beautiful, the surface is made of M 10 cement mortar, and the joint depth is 8 mm..3.2.5 The cement mortar is stirred on site by mortar mixer, and the mortar is transported by watertight containers such as iron drums or hopper cars. After the mortar is transported, its consistency and stratification must be checked. Mortar with insufficient consistency or layering must be re-stirred and can only be used after it meets the requirements. Mortar mixing must be carried out in strict accordance with the requirements of design and construction specifications, and manual mixing is strictly prohibited. When mixing, determine the mixing amount according to the masonry progress, so as to mix less and use quickly. Every time the mortar is mixed, it will be used up within 3~4 hours. Mortar that segregates or oozes in the transportation process or in the storage tank should be mixed again before masonry. Solidified mortar shall not be used. When transporting mortar in hot weather or rainy day, the container should be covered to prevent mortar from condensing or getting wet and losing its due fluidity. 3.2.7 Protection and maintenance of masonry (1) Don't throw stones or chisel stones on the masonry. Masonry that has been laid but the mortar has not solidified should not bear the load. (2) After the mortar is solidified, if the block is loose, it should be removed, scraped and cleaned, and then re-built. Demolition and reconstruction, shall not collide with adjacent stones. (3) When the new masonry works are finished, or when the works are finished, the masonry works should be covered with soaked linen. Under general temperature conditions, it is necessary to spray water for curing within 10~ 12 hours after masonry is completed, and within 2~3 hours after masonry is completed in hot weather, and the curing time is generally not less than 7~ 14 days. (4) When curing, the covering should always be moist. In general (15℃ and above), water at least once every 3 hours day and night, and at least once at night; Water it at least three times every morning and evening. (5) The newly-built mortar shall not be washed away by rain or submerged by water during the hardening process, especially the foundation masonry shall be carried out in the absence of water in the foundation pit. 3.2.8 C20 concrete construction platform for platform body is C20 concrete. After the foundation masonry is completed, the concrete construction of the abutment shall be carried out. The formwork must be firmly supported to prevent the formwork from falling off. The exposed surface shall be made of bamboo glue board or small formwork lined with thin plastic board, and the area of each formwork shall not be less than 2 square meters. The raw materials used in concrete must be tested in the laboratory and licensed. In strict accordance with the concrete construction ratio of blanking, mechanical mixing to ensure the workability of concrete. Concrete is poured symmetrically on both sides of the culvert, and the thickness of each layer is 30cm, and it is vibrated tightly to ensure the beauty of concrete inside and outside. Strictly control the width of concrete construction joints and staggered joints, the flatness of bedding face, the area and depth of surface honeycomb pits, and require staggered joints to be no more than 3mm, the flatness of bedding face to be no more than 5mm, the area of surface honeycomb pits to be no more than 0.3%, and the depth to be no more than 5 mm .. It is proposed to adopt a 2cm thick wooden template for construction projects. The fabrication and installation of formwork must meet the requirements of design and construction specifications, especially the end formwork at the settlement joint must be flat and on the same vertical line with the settlement joint of the wall and foundation. The concrete is centrally installed with a mixer at the site for mixing; Tamping adopts plug-in vibrator. In order to ensure that the cushion concrete is firmly connected with the wall, stalagmites are embedded at the top of the side wall when laying, and the construction joints are washed clean with pressure water before pouring concrete. After concrete pouring, the tongue-and-groove surface shall be compacted and leveled. After the final set of concrete, water shall be sprayed in time and covered with linen for curing. The curing time shall not be less than 14 days, and the surface shall always be moist. When the strength of concrete reaches 2.5Mpa and its edges and corners are not damaged by formwork removal, the formwork can be removed to ensure the real light inside and outside the concrete. 3.2.9 The cover plate construction shall be carried out according to the overall construction plan. The cover plate is arranged on the existing stone mouth service road (the specific position will be determined after the implementation of the bridge design scheme). After the cover concrete reaches the design strength, it will be transported to the construction site by 4t truck and manually transported to the construction site for installation. The formwork is made of factory-made steel formwork, and the joints of the formwork are padded with rubber sheets to ensure that the joints are tight and do not leak slurry. Template installation is shown in Figure 3 below. The steel bars are concentrated in the bridge steel bar processing shed, cut, bent and bound according to the design, and manually transported to the prefabrication yard for installation. The quantity, specifications and geometric dimensions of each protective layer steel bar after bending and binding must meet the design and specification requirements, and hook shall be embedded according to the design position and specifications. The concrete is mixed in the mixing station set on the bridge and transported to the pouring place by iron drum truck. Concrete mixing must be carried out in strict accordance with the selected theory and construction coordination. In order to speed up the turnover of formwork, FDN- 1000 early strength water reducer is added into concrete mixing. Tamp with plug-in vibrator. After concrete pouring, the top surface of the cover plate should be compacted and leveled, and then it should be leveled for the second time before the final setting to ensure the real light inside and outside the concrete. After the final set of concrete, water shall be sprayed in time and covered with linen for curing, and the curing time shall not be less than 14 days, and the surface shall be kept moist frequently. When the strength of concrete reaches 2.5Mpa and its edges and corners are not damaged by formwork removal, the formwork can be removed, and the formwork should be trimmed after being reused for three times to ensure the flatness of the formwork surface and the geometric dimensions after installation meet the design and specification requirements. When the concrete strength reaches the designed 100%, the cover plate can be transported and installed; Before the cover plate is installed, check whether the tongue-and-groove size, span and preformed size of the cover plates on both sides of the culvert meet the requirements, and only after the above dimensions meet the requirements can the cover plate be installed; When the cover plate is installed, mortar with a thickness of about 2cm should be laid at the tongue and groove to ensure that there is no gap between the bottom of the cover plate and the tongue and groove. The gap between two cover plates (except settlement joint) shall be filled with mortar. 3.2. 10 waterproof layer construction The waterproof layer of this culvert is Class A waterproof layer, and the asphalt used in the waterproof layer is petroleum asphalt, with softening point not lower than 50℃, penetration not lower than 30 (110 mm) and elongation not lower than 30cm. Boil asphalt in an open cauldron, and the asphalt in the cauldron shall not exceed 2/3 of its capacity. When boiling, measure the temperature with a high temperature thermometer. When the surface of asphalt stops foaming and the temperature reaches 175~ 190℃, stop heating and keep this temperature with warm fire for use. Boiled asphalt shall be transported to the construction site in a small iron drum, and the asphalt temperature shall not be lower than 150℃ when used. The surface of asphalt-coated masonry should be brushed to remove the slurry first, and the brushing work must be carried out in dry and warm weather (the temperature is not lower than 5℃). Asphalt must be fully paved, coated, smooth and uniform, with the same thickness, and there must be no defects such as wrinkles, damage, bubbling, warping, layering, sliding or lax sealing. 3.2. 1 1 Settlement joint construction This culvert is provided with a settlement joint every 5m. The construction of settlement joint should ensure that the structures on both sides of the joint can freely settle and prevent water leakage, so the settlement joint must run through the whole section (including the foundation). The concrete construction method of settlement joint is as follows: (1) 3cm thick asphalt impregnated wood boards are embedded in the foundation construction according to the design requirements. (2) The outer side of the wing wall joint is filled with hemp reinforcement soaked in hot asphalt, with a depth of 5cm, the inner side is filled with cement mortar M 10, with a depth of 15cm, and the middle is filled with clay. (3) The construction quality of settlement joint requires that the end face of settlement joint should be neat and square, the foundation and wall should not be staggered up and down, they must be well connected, and the embedded parts should be filled. 3.2. See Figure 4 for the process flow and construction progress of12. See Schedule 4 for the construction schedule of slab culvert. 4 Quality assurance measures The culvert construction is carried out in accordance with Technical Specifications for Highway Bridge and Culvert Construction (No.:TB10203-2002J162-2002). Standard for Quality Acceptance of Highway Bridge and Culvert Engineering (No.:TB10415-2003 J286-2004) and Code for Construction of Highway Concrete and Masonry Engineering (No.:TB10210-200/KLOC- And do the following work well in the construction process: 4. 556438 Figure 4 Culvert construction process flow chart 4.2 for detailed technical disclosure, so that the construction personnel can clearly understand the technical standards of each work and conscientiously implement them in the construction. 4.3 Strengthen measurement and recheck. 4.4 All raw materials and finished products must have a certificate of approval when they enter the site, and steel bars and cement must be re-examined to meet the design and specification requirements before they can be put into use. Unqualified materials and semi-finished products are absolutely not allowed to be used in the project. 4.5 Dig intercepting ditch at the top of the foundation pit, dig drainage ditches and wells around the bottom of the foundation pit, and equip with a water pump with good performance to discharge the water in the foundation pit in time. Foundation construction should be carried out in time after the acceptance of the basement, so as to avoid reducing the bearing capacity of the basement due to long exposure time. 4.6 The backfill soil of foundation pit must be compacted, and the drainage work should be done well to prevent the foundation from being soaked by water and reduce the bearing capacity of the basement. 5. Safety guarantee measures According to the actual situation of this culvert, we have formulated the following safety guarantee measures: 5. 1 Personnel involved in this culvert operation must wear specified protective clothing and articles, safety helmet and work shoes to work, and it is forbidden to wear slippers and go barefoot to work. 5.2 Before construction, the person in charge of construction shall make technical and safety disclosure seriously and comprehensively, and make clear the safety precautions. During construction, it is necessary to grasp the progress and quality at any time and eliminate unsafe factors in time. 5.4 Ensure the safety of electricity consumption in construction, prohibit violating the regulations on electricity consumption, and prohibit indiscriminate connection and use to prevent cable damage and leakage. It shall be operated by professional electricians. 5. 10 It is forbidden to work after drinking. 5. 1 1 When boiling asphalt, the boiling place should be located in the downwind of the construction site, and keep a certain distance from ordinary people, material piles, houses, etc. The asphalt in the pot shall not exceed 2/3 of the pot volume, and the personnel involved in asphalt boiling must wear labor protection articles and be equipped with fire extinguishers at the boiling place. 6. Guarantee measures for civilized construction 6. 1 Dig drainage ditch, rainwater and construction water are concentrated in the drainage ditch for discharge, and cross flow and scouring are not allowed everywhere. 7. Environmental protection measures 7. 1 Earthwork for foundation excavation shall be abandoned according to regulations, and necessary measures shall be taken to prevent soil erosion. 7.2 The construction shall minimize the damage to the surrounding environment, especially to farmland water conservancy. 7.3 Do a good job in dredging the drainage and irrigation system on the construction site, and do not destroy the surrounding farmland and its water conservancy facilities.