When designing pump equipment foundation, the following information should be obtained: (1) model, speed, power, specification and outline dimension diagram of pump equipment; (2) weight and center of gravity position of machine or mass distribution diagram of compressor, motor and auxiliary equipment; (3) foundation template diagram and top surface design of foundation Elevation, thickness of secondary grouting layer, location and specification (or size) of anchor bolt (or anchor bolt hole); (4) coordinate position of equipment foundation in production device; (5) engineering geological and hydrogeological survey data of construction site
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Requirements for the foundation: (1) the foundation should sit on the old soil layer; (2) when there is no special requirement for the settlement of the pump equipment foundation whose power is less than 100kW, it can be set in the backfilled soil which has been tamped by layers, and its compaction coefficient should not be less than 0.93; (3) the top surface of the foundation should not be less than 200 mm above the ground, and its buried depth should not be less than 0.8 m, and not less than the frozen depth The buried depth should be 0.5m below the arable soil layer; (4) allowable deformation value of equipment foundation: allowable deformation value of equipment foundation category center settlement (mm) inclined atmospheric pressure device high pressure device pump foundation centrifugal pump 0.002 piston pump power ≥ 500kw100 ~ 20050 ~ 1000.002 piston pump power ≤ 500kw0.0033 : the foundation mass shall be greater than 3 ~ 5 times of the machine mass; P ≤ (0.5 ~ 0.7) f, where p is the design value of average static pressure at the bottom of the foundation, kPa; F is the design value of foundation bearing capacity, kPa; the total center of gravity of the foundation group and the centroid of the bottom of the foundation shall be located on the same vertical line, and the relative eccentricity shall not exceed 3%; (2) the concrete grade of the foundation shall be C20, and the cushion shall be C10; (3) the concrete quality of the foundation When the soil volume is less than 20m3, the surface structural reinforcement can not be configured; when the concrete volume is 20 ~ 40m3, the reinforcement mesh with diameter of 10mm and spacing of 200mm shall be configured on the top surface of the foundation; when the concrete volume is more than 40m3, the reinforcement mesh with diameter of 10 ~ 14mm and spacing of 200 ~ 300mm shall be configured on the surrounding, top and bottom surfaces of the foundation; the upper and lower side reinforcement shall be configured on the cantilever part of the foundation slab according to the strength calculation When the cantilever length of the bottom plate is less than the thickness of the floor, reinforcement is not necessary; (4) the thickness of the secondary pouring layer on the top of the foundation should be 30 ~ 50 mm, and the material should be fine aggregate concrete, whose strength grade should be one grade higher than that of the foundation concrete; when the thickness is less than 30 mm, 1:2 cement mortar can be used; the exposed part of the foundation should be plastered with 1:2 cement mortar; (5) homemade anchor bolts The straight hook type should be adopted, and the length of straight hook section should not be less than 4D (D is the diameter of anchor bolt); the embedding depth l should not be less than 20 times of the diameter, and for the anchor bolt with anchor plate, it should not be less than 15 times of the diameter, and the constructional bolt should not be subject to this limit, and it should not be less than 300mm; the embedding method should adopt the pre reserved hole, and the distance from the bottom of the reserved hole of the anchor bolt to the bottom of the foundation should not be less than 100mm; the bottom of the anchor bolt The distance to the bottom of the reserved hole shall not be less than 50 mm; the distance from the edge of the reserved hole to the edge of the foundation shall not be less than 100 mm; when the bolt is embedded, it shall not be less than 100 mm when the diameter is less than 20, and it shall not be less than 150 mm when the diameter is more than 20
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If not, reinforcement mesh with diameter of 6 ~ 8mm and spacing of 100 ~ 150 mm should be provided; in the reserved hole, C25 fine aggregate concrete with concrete strength grade or higher foundation concrete strength grade should be used; when the side length of rectangular foundation and perimeter of circular foundation are more than 40 m, post pouring belt with width of 50 cm should be set, and the reinforcement should not be cut off, which will be one grade higher than the original foundation one month after the pouring of bottom plate The concrete with micro expansion agent should be poured at one time without construction joint
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When the construction joint must be reserved, the construction joint structure and operation requirements shall be strictly observed
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When the concrete strength reaches more than 70%, the equipment can be installed
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Dynamic calculation of centrifugal pump: (1) when the standard value of foundation bearing capacity is not less than 80kPa, motor power is not more than 560kw, and the mass of centrifugal pump foundation is not less than three times of the mass of the machine, dynamic calculation can be omitted; (2) when the foundation needs dynamic calculation, the allowable amplitude of the foundation shall comply with the allowable amplitude of the foundation specified in the table below [a]; the number of machine working revolutions n (R / min) [a] (mm) 1000 ≥ n > 750 10 750 ＞ n ≥ 5 000.15 n ＜ 5 000.20 (when n > 1 000 R / min, the allowable amplitude [a] can be determined according to the requirements of the manufacturer, or 0.1 mm) (3) the disturbing force value of the centrifugal pump is calculated by the following formula: PN = mew2, where: · PN – disturbing force value of the centrifugal pump (n); · e – eccentric distance of the centrifugal pump (m); · W – circular frequency of the disturbing force of the machine (1 / s), w = 0.105 n; · m – mass of the rotating part of the motor (kg)
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2、 Pump foundation design 1
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General requirements (1) the pump foundation design must be safe and stable, with accurate elevation and size, so as to ensure the stable operation of the pump and convenient installation and maintenance
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(2) According to GB / t50265-97 “code for design of pumping stations”, the dynamic calculation of the pump foundation of the vertical axial-flow pump unit with single power less than 160kW and the horizontal centrifugal pump unit with single power less than 500kW is not necessary
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On the contrary, it must be calculated, especially the pump foundation connected with the pump house building structure as a whole
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Key points of horizontal centrifugal pump foundation design (1) foundation form: according to the connection with the pump house structure or not, it can be divided into separate type and integral type
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The ground pump house should adopt the separated foundation, and the underground or semi underground pump house generally adopts the integral type, which is connected with the reinforced concrete bottom plate as a whole
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The integral foundation belongs to the structural design content of the pump house
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(2) Generally, when the power is below 100kW, the water pump and motor have chassis, which can be directly installed on the foundation; when the power is above 100kW, there is no chassis, and the foundation surface needs to be padded with steel plate or section steel
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(3) Due to the frequent update and change of water pump and motor equipment, the product specifications of various manufacturers are not completely unified
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Therefore, in the construction drawing design, we must obtain the product technical description and other information of the manufacturer
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Before pouring and tamping the foundation, it is best to check according to the size of the actual equipment
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(4) For the separated medium and small pump foundation, the following empirical data can be used for reference; the integral foundation can be adjusted according to the situation, and combined with the structural design of the pump house
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The foundation material is usually not less than C20 concrete; after the anchor bolt is embedded, the reserved screw hole shall be filled with not less than C25 fine concrete for consolidation
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The embedded length of foundation bolt shall not be less than 20 times of bolt diameter (L ≥ 20d), and the length of bolt fork tail shall be 4D bolt; the depth of reserved screw hole shall be greater than the total embedded length of bolt by 3-5cm
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The horizontal water pump is generally a block foundation, and its size is generally determined according to the data provided by the installation size of the selected water pump and motor
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If there is no above data, it can be determined by referring to the following data
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A
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For the small pump with base: the length of foundation L = the length of base L1 + (0.20 ~ 0.30) (m)
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Foundation width b = base screw hole spacing (in width direction) B1 + 0.30 (m)
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Foundation height h = length of foundation screw L2 + (0.10 ~ 0.15) (m).
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