The plastic drainage belt which is damaged or polluted may not be used in the project. The sand filling amount of 5.3.2 sand well should be calculated according to the volume of well bore and
the dry density of sand in the medium density condition. The actual sand filling quantity of the sand well should not be less than 95% of the calculated value. Poured into the sand in the sand should be used for sand, and should make dense. 5.3.3 plastic drainage belt and bag sand well construction, should be configured to detect the depth of the equipment. 5.3.4 plastic drainage belt used in the construction of the casing should ensure that the insertion of the tape does not distort the foundation. Plastic drainage belt need to take a long time, should use the membrane inner core belt flat lap connection method, lap length should be greater than 200mm. The inner diameter of casing used in sand bag well is slightly larger than that of sand well diameter. Plastic drainage belt and bag sand well construction, plane spacing deviation should not be greater than the hole diameter, the vertical deviation should not be Greater than 1.5%, the depth shall not be less than the design requirements. Plastic drainage belt and bag sand well buried sand sand cushion in length shall not be less than 500mm. 5.3.5 on the preloading project, in the process of loading should be carried out the vertical deformation, the lateral pile horizontal displacement and pore water pressure and other projects, and according to the monitoring data to control the loading rate. On the vertical drain ground, the maximum vertical deformation amount every day should not exceed 15mm, the natural foundation, the maximum vertical deformation amount every day should not exceed 10mm; side pile horizontal displacement of every day should not more than 5mm, and should be based on the observation data analysis, estimate the foundation stability. (II) true air pre pressing 5.3.6 vacuum preloading pumping equipment are advised by jet vacuum pump, air pumping must reach the vacuum suction 95kPa above, vacuum pump set should be according to pre press area size and shape, vacuum pump efficiency and engineering experience to determine, each pre compression zone shall have at least two vacuum pumps. 5.3.7 vacuum pipeline connection should be strictly sealed in vacuum pipeline should be installed in the valve and check valve. The horizontal distribution of water pipes can be used to strip, and comb shaped feather and
other forms of filter pipe layout to form a loop. The filter pipe should be located in the sand cushion, which is covered with sand layer thickness of 100 to 200mm. The filter pipe can be made of steel pipe or plastic pipe, and the water filter material, such as nylon yarn or earthwork fabric, is outsourced. 5.3.8 sealing film should be anti aging performance, good toughness, strong anti puncture performance of the impermeable material. The sealing film is sealed to use double hot flat seam lap, lap width should be greater than 15mm. Sealing film is suitable for laying layer and peripheral membrane can be buried in the membrane, and tiling with sticky covering blank holder, confining twist of the trench and membrane overlying the methods such as water sealing by trenching. 5.3.9 the vacuum surcharge preloading, vacuum, when the vacuum pressure reaches the design requirement and stable, surcharge, and continue to pump gas, heaped load required in membrane laying woven geotextiles fabric protective material. 5.4 quality inspection 5.4.1 construction process quality inspection and monitoring should include the following: 1 plastic drainage belt must be in a random sample of live sent to a laboratory for testing performance index and the performance index including longitudinal through content, complex tensile strength, membrane tensile strength, membrane permeability coefficient and the equivalent aperture and so on. 2 the particle analysis and permeability test must be carried out in the sand well and sand layer sand layer of different sources. 3 for an important project with anti slide stability control, should be in the preloading zone selected representative sites reserved holes, at different stages of loading of in-situ vane shear test and sampling of indoor soil test. 4 the monitoring of the project, such as vertical deformation, lateral displacement and pore water pressure, should be carried out. 5 in addition to the monitoring of the foundation deformation and pore water pressure, the vacuum preloading project should be carried out under the condition of the vacuum preloading. Measurement of degree and underground water level. 5.4.2 pre pressing method for final acceptance inspection shall conform to the following requirements:
1 the vertical deformation and the average degree of consolidation of the vertical and the bottom of the shaft under the pressure of the vertical and the vertical deformation and the average degree of consolidation should meet the design requirements. 2 in situ vane shear test and laboratory soil test for the foundation soil. When necessary, it should be carried out in the field load test, the number of tests should not be less than 3 points. 6 dynamic compaction method and dynamic compaction replacement method 6.1 general provisions 6.1.1 dynamic compaction method is suitable for the treatment of gravel soil, sand, low saturation of silt and cohesive soil, collapsible loess, soil fill and miscellaneous fill foundation. Dynamic compaction replacement method is suitable for high saturation of silt and soft plastic to flow plastic clay and other foundation on the deformation control requirements of the project. 6.1.2 dynamic compaction replacement method in the design before the field test to determine its application and processing results. 6.1.3 strong ramming and strong tamping replacement construction before, at the construction site of a selection of one or several test area representative on site, compaction test or test construction and test area number should be determined according to the construction site complex degree, the size of the building and building types. 6.2 design Dynamic consolidation method (I) The effective reinforcement depth of 6.2.1 dynamic compaction method should be determined according to the field test or local experience. In the absence of test data or experience can be predicted by table 6.2.1. Table 6.2.1 effective reinforcement depth (m) Click to be able to (m, Kn) gravel soil, sand, etc. Coarse granular soil, cohesive soil, collapsible loess and other fine granular soil One thousand Two thousand
Three thousand Four thousand Five thousand Six thousand 80005 ~ 6 6~7 7~8 8~9 9 ~ 9.5 9.5 ~ 10 10 ~ 4 ~ 5 ~ 10.5 5~6 8 ~ 8.5 8.5 ~ 9 Note: the effective reinforcement depth of dynamic compaction method should be calculated from the initial dynamic compaction surface. 6.2.2 the number of rammed points, shall be according to the field test of the dynamic compaction and settlement of the relationship between the curve determined, and should also meet the following conditions: L the last two hit average consolidation settlement amount should not exceed the following values: when click tamping energy is less than 400 kn, M is 50mm; when you click the tamping hammer to 4000 ~ 6000kn - m to l00mm; when click tamping energy is greater than the 6000kn M is 200mm. 2 the ground around the hole should not be too large; 3 do not because of the hole too deep and difficult to lift the hammer.
According to the properties of the foundation soil, the 6.2.3 compaction times should be determined according to the properties of the foundation soil, which can be used for 3 ~ 2 times, for the fine granular soil with poor permeability. In the end, with the low energy full 2 times, the dynamic compaction can be used in the light hammer or low pitch hammer, hammer and seal. There should be a certain period of time between the 6.2.4 two times.Time depends on the time of the dispersion of the water pressure in the soil. When the lack of measured data, according to the permeability of the foundation soil, for the poor permeability of cohesive soil foundation, the interval time should not be less than 3 ~ 4 weeks; for the permeability of the foundation can be a good continuous compaction. 6.2.5 tamping point position according to the plane shape of the substrate, the equilateral triangle, isosceles triangle or a square. The first pass of the dynamic compaction point of 2.5 to 3.5 times the diameter of the desirable ram hammer, the second times the dynamic compaction point is located between the first pass to the point of compaction. After the dynamic compaction of the point can be reduced to the appropriate distance. To deal with the depth of the deep or click the hammer can be a larger project, the first round of the point spacing should be appropriate to increase the compaction. 6.2.6 tamping treatment scope should be greater than the range of building foundations, each side beyond the width of the outer edge of the base should be for substrate designed to deal with the depth of 1 / 2 to 2 / 3, and should not be less than 3m. According to the preliminary determination of the dynamic compaction parameters, the dynamic compaction test scheme is proposed, and the field test is carried out in the field of 6.2.7. According to different soil conditions to be tested after the end of one to a few weeks after the test, the test site for testing and comparison with the test data before the test, test the effect of dynamic compaction, determine the dynamic parameters of the project. 6.2.8 strong ramming foundation bearing capacity characteristic value should be through field loading tests, preliminary design can also be according to the dynamic in situ test and soil test index according to the current national standard of the code for design of building foundation GB 50007 relevant provisions to determine. 6.2.9 dynamic consolidation foundation deformation calculation should conform to the existing national standard "building foundation design code" GB 50007 relevant provisions. After compaction, the compressive modulus of the soil layer in the effective reinforcement depth should be determined by in situ test or geotechnical test. (II) strong tamper with clean 6.2.10 dynamic compaction replacement of the depth of the pier by the soil conditions, in addition to thick layer of saturated silt, should penetrate the soft soil, reaching the hard soil, the
depth should not exceed 7m. According to the field test, the dynamic compaction replacement method of 6.2.11 can be determined according to the field experiment. 6.2.12 pier body material can be a good grading block stone, gravel, slag, construction waste and other hard coarse particulate materials, particle size of more than 300mm of the particle content should not exceed 30% of the total weight. 6.2.13 the number of rammed points should be determined through the field test, and the following conditions should be met at the same time: 1 pier bottom through the soft soil, and reach the design of pier length; 2 the cumulative amount of ram is 1.5 ~ 2 times of the length of the design; 3 the average of the last two strikes is not larger than the provisions of article 6.2.2 of this code. 6.2.14 pier position should adopt an equilateral triangle or square. On the basis of the independent foundation or strip foundation can be arranged according to the shape and width of the foundation. 6.2.15 asked the pier distance according to load and the bearing capacity of soil is selected, when full arrangement desirable when the diameter of the hammer is 2 to 3 times. 1.5 ~ 2 times of the diameter of the independent foundation or the strip foundation is desirable. The calculated diameter of the pier is 1.1 to 1.2 times of the diameter of the hammer. 6.2.16 when the net distance between the piers is larger, the upper structure and foundation stiffness should be improved. 6.2.17 dynamic compaction replacement processing range shall be executed in accordance with section 6.2.6 of this specification. 6.2.18 pier top should be laying a layer of thickness of not less than 500mm of the compacted cushion, cushion material can be the same as the pier body, particle diameter should not be greater than 100mm. When the 6.2.19 dynamic compaction replacement is designed, the ground elevation value should be estimated, and the correction of the dynamic compaction. 6.2.20 strong tamping replacement test scheme determined, should comply with the provisions of article 6.2.7 the specification, test items, except the bearing capacity and deformation modulus of the field loading test, there should be using super heavy or heavy dynamic penetration method, check replacement pier bottom case and bearing force and density changes
with depth. 6.2.21 determine soft clayey soils of strong tamping replacement pier foundation bearing capacity characteristic value, only considering pier, does not consider the effect of soil between the piers, the bearing capacity shall be determined by in situ single pier load test, of saturated silt can be considered according to the composite foundation, the bearing capacity can be determined by field single pier loading test of composite foundation. The calculation of the deformation of the replacement foundation with 6.2.22 dynamic compaction shall conform to the provisions of article 7.2.9 of this code. 6.3 Shi Gong 6.3.1 tamping hammer quality desirable 10 ~ 40t, the bottom surface of the form should be adopted in circular or polygonal, hammer bottom area should be determined according to the nature of the soil, hammer bottom static earth pressure value desirable 25 ~ 40 kPa, the fine grain soil hammer at the end of static ground pressure Smaller values should be taken. The bottom surface of the hammer is symmetrically provided with a plurality of exhausting holes communicated with the top surface thereof, and the aperture of the hammer is 250 to 300mm. It is desirable to 100 ~ 200kPa for the static earth pressure at the bottom of the replacement hammer. 6.3.2 construction machinery should adopt the crawler crane with automatic hook device or other special equipment. The crawler crane, on the end of the arm part is arranged auxiliary door frame, or other security measures to prevent the drop frame overturning. 6.3.3 spot surface soft soil or groundwater level is high, tamp the bottom water on the construction, the appropriate use of artificial lower underground water level or shop to fill a certain thickness of loose material, the underground water level is lower than the bottom surface of the 2m. Pit or site water should be removed in a timely manner. Before the construction of 6.3.4, we should find out the location and standard of the underground structures and all kinds of underground pipelines, and take the necessary measures to avoid the damage caused by construction. 6.3.5 when the strong and poor construction of the vibration of the nearby buildings or equipment will produce harmful effects, should be set to monitor points, and to take the same vibration or vibration isolation or vibration isolation measures. 6.3.6 dynamic compaction construction can be carried out according to the following steps: 1 clean up and smooth the construction site;
2 mark the first pass of the site, and measuring the height of the site; 3 the crane is in place, and the ram is put in the place of the ram; 4 to measure the height of the top of the hammer; 5 rammed hammer is lifted to a predetermined height, open decoupling device, to be rammer decoupled free fall, put down the hook, the top elevation of the measuring ram, if found due to the bottom because of the inclination of rammer skew, should be timely leveling the bottom; 6 repeat step 5, according to the design requirements of the number of compaction and control standards, the completion of a dynamic compaction; 7 for the dynamic compaction point, repeat steps 3 to 6, complete the first pass of the full dynamic compaction; 8 with a bulldozer rammed pit filled, and measure the ground elevation; 9 after a specified time interval, finish all tamping times according to the steps of successive, finally with low energy full compaction, ground surface soil compaction and measurement site elevation after compaction. 6.3.7 dynamic replacement construction can be carried out according to the following steps: 1 clean up and smooth the implementation?Wu was "North's fan Xing Ping Huai Su Xi lie stupid good?.0 ~ 2.0m gravel cushion construction; 2 mark the location of the dynamic compaction, and measure the site elevation; 5 the dynamic compaction and the depth of dynamic compaction. When the ram is too deep and the hammer is difficult to stop, fill up to the hole and the hole flat, record the number of filler, so repeat until meet the requirements of the dynamic compaction and control standards to complete a pier compaction. When the influence of soft soil around the consolidation point of the construction, can be cleaned at any time and the gravel around the point, to continue construction; 6 according to the inside out, the principle of every line to complete the construction of the whole point of the dynamic compaction; The 7 level ground, full compaction with low power will loosen site surface compaction, and measure the dynamic field of elevation; 8 laying cushion layer, and lamination compaction.
6.3.8 in the process of construction should be responsible for the following monitoring work: Before opening the L, the weight and the distance of the ram should be checked to ensure that the energy of the hammer is in accordance with the design requirements; 2 in each pass before the hammer, to deal with the dynamic compaction point of the line for review, after the inspection of the location of the ram, found that deviation or leakage of the dynamic compaction should be promptly corrected; 3 according to the design requirements to check the dynamic compaction of each point of the number of times and the weight of each impact. The replacement depth of dynamic compaction replacement should be checked. 6.3.9 in the construction process to deal with the parameters and the situation of detailed records. 6.4 quality inspection 6.4.1 inspection of the construction process of the test data and construction records, do not meet the requirements of the design should be supplemented or take other effective measures. Dynamic compaction with ultra heavy and heavy cone dynamic penetration test replacement pier replacement construction in the background of prayer. 6.4.2 after dynamic compaction foundation completion and acceptance of the bearing capacity test, should be after the end of construction in a certain interval of time can be, for gravel soil and sandy soil, the time interval for the desirable 7 to 14 days. Silt and clay is desirable from 14 to 28 days. The interval time of dynamic compaction replacement foundation is 28d. After the completion and acceptance of 6.4.3 strong poor treatment, the bearing capacity test should be used in situ test and laboratory soil test. Foundation strong poor replacement after the completion of the inspection, bearing force test in addition to the single pier load test, there should be the dynamic penetration and effective means to identify replacement pier with background and bearing capacity and density changes with the depth, of saturated silty soil foundation allows single pier loading test is replaced by a single pier composite foundation load test. 6.4.4 completion and acceptance of bearing the number of test force, should be determined according to the importance of site complexity and buildings, for simple site on the buildings, each building on the foundation load test point should not less than 3 points; for complex site or important building foundation should increase the points test. The test of the load test and the replacement of the bottom of the pier with dynamic compaction replacement shall not be less than the l%, and shall not be less than 3 points. 7 vibrofloatation
7.1 a sort of rule 7.1.1 vibroflotation method is applicable to the treatment of sand, silt, silty clay, plain fill and miscellaneous fill foundation. For the treatment of saturated cohesive soil and saturated loess foundation, the non drainage shear strength is not less than 20kPa, the applicability of the method should be determined before construction. No filler vibro compaction for medium sand and coarse sand foundation in clay content is less than 10%. 7.1.2 for large, important or site formation complex engineering, before the formal construction should be determined by the field test results. 7.2 design 7.2.1 vibroflotation pile should be determined according to the importance of the buildings and site conditions, when used in multi-storey buildings and high-rise buildings, should at the outer edge of the base to expand 1 ~ 2 row piles. When asked to eliminate liquefaction, expand the width of not less than the substrate under the liquefiable soil thickness of 1/2 based on edge. 7.2.2 pile layout, to a large area of Mantang processing, the advisability of using either the equilateral triangle arrangement; of separate foundation or strip foundation, the advisability of using either square or rectangular, or isosceles triangle arrangement. 7.2.3 vibratory pile spacing should be according to the upper structure load size and site soil conditions, and combined with the vibrator power size into account. The use of 1.3 ~ 2.0m; 55kW vibrator cloth pile spacing can be used 1.4 ~ 2.5m; 75KW vibroflot pile layout asked from the 1.5 ~ 3.0m 30kW vibrator cloth pile spacing. Large load or the use of less distance to the cohesive soil, the load is small or the sand should adopt a larger spacing. 7.2.4 determination of pile length: when the relatively hard layer buried, according to relatively hard layer depth determined; when the relatively hard layer depth are large, according to the building foundation deformation allowed values are determined; the liquefied foundation, pile length should be in accordance with the requirements of seismic processing depth determination. Pile length should not be less than 4m. 7.2.5 between the pile and the foundation should be laid a layer of 300 ~ 500mm thick gravel cushion. 7.2.6 pile material can not be more than 5% of the amount of mud, gravel, gravel, slag or other stable performance of the hard material, it is not suitable for the use of weathered stone. The commonly used packing size: 30kW vibroflot 20 ~ 80mm; 55kW vibroflot 30 ~ 100mm; 75KW vibroflot 40 ~ 150mm. The average diameter of 7.2.7 vibratory pile according to each pile with filler volume calculation.
7.2.8 vibroflotation pile composite foundation bearing force characteristic value should be through the field loading test of composite foundation, preliminary design also available for single pile and pile soil bearing force characteristic value press estimated: Skpkspkfmmff (1) = (7.2.8-1)? 22/eddm= (7.2.8-2) Characteristics of vibroflotation pile composite foundation bearing capacity in value (kPa); SPKF PKF - pile bearing capacity characteristic value (kPa), it is appropriate to determine the load test by single pile; SKF - the characteristic value of soil bearing capacity (kPa), which is suitable for the local experience, such as no experience, it is desirable that the natural foundation bearing capacity characteristic value; M - the replacement rate of pile and soil area; D - the average diameter of pile (m); Ed - the equivalent circle diameter of the foundation area treated by the root pile; Equilateral triangle pile sde5.1= Square cloth se13.1= D Rectangular cloth pile 2113.1ssde= S, respectively, the pile spacing, vertical spacing and lateral spacing. 1s2s The bearing capacity characteristic value of composite foundation can be pressed down by the preliminary design of the cohesive soil foundation, especially in the field load test data: (7.2.8-3) [skspkfnmf (1) = 1?]] Stress ratio of pile and soil, in the absence of measured data, it is desirable to 2 ~ 4, low strength of the original soil to take a large value, the strength of the original soil to take small values of n The calculation of deformation 7.2.9 vibroflotation foundation should be consistent with currentRelevant provisions of the national standard "code for design of building foundation" GB 50007. The compression modulus of the composite soil layer can be calculated by pressing:
[sspEnmE (1) (7.2.9) = 1? Composite soil compression modulus (MPa); spE SE - pile soil compression modulus (MPa), should be based on local experience, such as no experience, it is desirable to the compression modulus of natural foundation. In the formula (7.2.9) of the pile soil stress ratio, in the absence of measured data, the viscosity on the desirable 2 ~ 4, the silt And sand on the desirability of 1.5 ~ 3, the strength of the original soil is low, the strength of the original soil to take small values. 7.2.10 without filler vibro flush encryption should be in the preliminary design stage of the technics test in site, the possibility of determining no filler vibro, bar distance, electric current of vibrating compaction density, vibroflotation water pressure, the vibration of the sand layer of the physical and mechanical indexes. 30kW vibrator compaction depth should not exceed 7m, 75kW vibrator should not exceed 15m. 7.2.11 no filler vibro compaction pitch can be 2 ~ 3M, should use an equilateral triangle hole. 7.2.12 without filler vibro flush encryption foundation bearing force characteristic value should be through field loading tests, preliminary design o according to the encrypted in situ test index according to the current national standard of the code for design of building foundation GB 50007 relevant provisions to determine. 7.2.13 without filler vibro flush encryption foundation deformation calculation shall be in accordance with the current national standard of the code for design of building foundation GB 50007 relevant provisions of the. The compression modulus of the soil layer in the depth of the encryption should be determined by in situ test. 7.3 Shi Gong 7.3.1 vibroflotation construction according to the level of design load size, soil strength, design pile length conditions using different power of vibrator. Before the construction, the test should be carried out in the field to determine the hydraulic pressure, the density current and the time of the stay. Crane, lifting machinery available 7.3.2 vibroflot self-propelled derrick type construction car or other suitable equipment. Construction equipment should be equipped with the current, voltage and time to stay automatic signal. 7.3.3 vibration construction can be carried out according to the following procedures:
1 clean up the formation of the construction site, the layout of the pile position; 2 construction equipment in place, so that the vibrator is aligned with the pile location; Start the water pump and vibrator, hydraulic available 200 ~ 600kpa, water is available 200 to 400L/min. The vibrator slowly sinking into the soil, pore velocity should be 0.5 ~ 2.0m/min, until reaching the design depth. The depth of the recording vibrator pressure, current and load time. 4 make hole behind the lifting vibrator while flushing until the hole, put to the bottom of the hole, repeat two or three times expanding aperture and the mud thinning, began filling pile. 5 high power vibrator feeding a proposed orifice, small power vibrator under difficult material, the vibrator is proposed for orifice packing, each packing thickness should not be more than 50cm. The vibrator sunk to the bottom of the packing density vibration of pile, when the current reaches the provisions of the dense current value and a specified retention time of vibration after, vibroflotation device improvement of 30 ~ 50cm. 6 repeat the above steps, bottom-up piecewise pile making until orifice, record sections of the depth of the filler amount, the final current value and keep the vibration time, and shall comply with the design requirements. 7 close the vibrator and the pump. 7.3.4 construction site should be prior to the opening of the slurry system, or the organization of good luck slurry vehicles will be transported to the pre arranged storage location, should be set up as long as the sedimentation tank reuse. After the construction of 7.3.5 pile, the loose pile should be reserved for the top of the top, if the loose pile head should be compacted, and then lay and compacted. 7.3.6 without filler vibro flush encryption should be used in high-power vibrator, in order to avoid creating holes in the sand from collapsing clinging to the vibrator, sinking speed should be fast, pore velocity should be 8 ~ 10m / min, after the arrival of the depth will shoot water is reduced to the minimum, left to the vibration compacting current reaches the stipulated time, lift the 0.5m, piecewise ternary until orifice, general per meter vibration dense time is about 1 minute. In the coarse sand in construction such as the case of difficult to sink, on both sides of the vibroflotation device increase welding auxiliary water tube, the increase of pore water, but pore water pressure should be small. 7.3.7 vibration dense hole construction sequence should be conducted along a straight line point by point.
7.4 quality inspection 7.4.1 check vibroflotation construction the construction records, such as missing or do not meet the requirements of the pile or vibroflotation points should be doing or to take effective remedial measures. The end of the 7.4.2 vibrator, except for sand, should ask every time before it can carry out quality inspection. The interval time of silty clay foundation is 21 ~ 28d, and it is good to be 14 to 21d. Quality inspection for construction of 7.4.3 vibratory pile by pile load test, test number is 0.5% of the pile quantity, is not less than 3. Random inspection of the crushed stone pile test can be used for heavy dynamic contact. The pile soil test in the treatment can be asked with depth of standard penetration test, static cone penetration test. 7.4.4 vibroflotation foundation after the completion of inspection, the bearing test should be used in the loading test of composite foundation. 7.4.5 composite foundation load test should not be less than 0.5% of the total number of piles, and each monomer project should not be less than 3 points. 7.4.6 for no filler vibro compaction treatment of sandy soil. The acceptance of bearing force test should be using the standard penetration test, dynamic penetration test and load test or other suitable test method. Check point should be in on behalf of lots or the foundation soil is poorer, and is located in the vibroflotation enclosed unit at the centroid and Vibro Replacement Center. The number of test for the number of vibroflotation 1%, a total of not less than 5 points. 8 sand and gravel pile method 8.1 a sort of rule 8.1.1 sand gravel pile method is suitable for the compaction of loose sand, silt, clay, soil, miscellaneous fill and other foundation. On the saturated clay foundation, the control of deformation can not be strictly controlled. Sand gravel pile method can also be used to deal with liquefied foundation. 8.1.2 the use of gravel pile foundation should be added to the treatment of the design, construction of the relevant technical information. Of the clayey ground, proper soil undrained shear strength index; of sand and silt foundation should be the foundation soil natural void ratio, relative density and standard penetration hit numbers and sand material properties, construction equipment and performance data. The design and quality inspection of the foundation, such as sand gravel pile, compacted element, and miscellaneous fill, should be in conformity with the relevant provisions of the fourteenth
chapter of this code, which is still in accordance with the chapter of this code. 8.2 design 8.2.1 sand pile hole Weiyi with equilateral triangle or square arrangement. The diameter of sand gravel pile can be 300 ~ 800mm, which can be based on the soil condition and the foundation of the foundation.