1, wrong understanding of quota and valuation documents, leading to engineering valuation errors.
1. 1) When the punching depth of the punching pile machine exceeds 40m, the subsection pricing (40-50m section and 50-60m section) is wrong. The correct way is to multiply the whole length by a higher coefficient. For example, if the pile length is 60,40-60m, the unit price of the whole section will be increased by 50% according to the labor consumption, and the shift consumption of percussion drilling machine will be increased by 60%.
1.2) Environmental protection error should be based on the quota of manual soil loading and loading of dump trucks in construction projects. The correct way is to load and unload the trucks that load and unload the garbage collection according to the manual work in the decoration project.
1.3) The aerated concrete block masonry with special mortar is wrongly priced according to the current mixed mortar (the material consumption is mixed mortar M5(32.5)). The correct way is to calculate the price according to the dry-mixed mortar (in which the material dosage is the special masonry mortar for aerated concrete).
2. The valuation error is caused by the calculation error of the project.
2. 1) The package price calculation of the post-cast strip concrete and formwork for the foundation, beam, slab, wall and other components.
2.2) The basement floor, roof, reinforced concrete roof, terrace and water tank are wrongly priced according to ordinary concrete. The correct way is to price according to waterproof and impervious concrete.
2.3) When the concrete strength of column (wall) is higher than that of beam (slab) by 5MPa, the concrete strength grade of the joint area of beam-column (wallboard) should be the same as that of column (wall), but the price of this joint is wrongly set according to the concrete strength grade of beam (slab).
2.4) The thickness of the end column is greater than that of the shear wall, and the formwork is staggered with straight walls or rectangular columns. The correct way is to apply the template quota of wall column.
2.5) elevator shaft wall template error should be counted as wall template; The correct way: press the wall template.
3. Unclear calculation rules of beam-slab formwork for sloping roof caused pricing error.
3. 1) Correct way: based on the design inclination angle of the roof (the included angle between the inclined plane and the horizontal plane), the sloping roof with the design inclination angle ≤ 15 shall be calculated according to the beam-slab quota project.
3.2) 15 & lt； For the inclined roof with a design slope of < 25, it shall be calculated according to the bottom formwork, and the beam-slab formwork quota shall be multiplied by the coefficient 1.05.
3.3) For the sloping roof with a design gradient of > 60, it shall be calculated according to the upper and lower double formwork support, and the wall formwork quota shall be applied;
3.4) The inclined roof with a design inclination of 25 ≤ 60 shall be calculated according to the upper and lower double-sided formwork, and the beam-slab inclined roof formwork quota project shall be applied.
4, not familiar with the design requirements of steel specifications, resulting in pricing errors.
In the general description of structural design, φ means HPB300 steel bar (grade I steel bar FYV = 270 N/mm2) (Code for Design of Concrete Structures (version 20 10) GB500 10-20 10, 4.2.3), and people who are not familiar with it are in.
For structures with seismic fortification requirements, the performance of longitudinal reinforcement should meet the design requirements; When there are no specific requirements in the design, the longitudinal reinforcement in the frame and diagonal bracing members (including ladder sections) designed according to the first, second and third seismic grades should adopt HRB335E, HRB400E, HRB500E, HRB335e, HRB400e or HRB500e, and the measured values of the maximum strength and total elongation should meet the following requirements: 65438+. (Strong yield ratio) 2 The ratio of the measured yield strength of steel bars to the standard yield strength should not be greater than1.30; (Super-strength ratio) 3 The total elongation of reinforcement under the maximum stress should not be less than 9%.
Re-examination: design value of ordinary steel bar strength (N/mm2)
5. The price of roof slope finding package does not meet the design requirements.
The thinnest part is 30 thick LC5.0 lightweight aggregate concrete, and 2% of the slope is staggered. The price of fine stone concrete laid on a hard foundation is set at 30 mm. Correct practice: the average thickness should be calculated according to the roof length, and the semi-finished fine stone concrete should be replaced with 50# slag concrete.
6. Conversion of missing coefficient when applying similar project quota.
The project consumption quota is compiled according to the general project. Some similar projects need to be converted by applying for corresponding quotas. Pay special attention to the quota annotation adjustment module in pricing software. After applying the quota, click [Quota Adjustment] in the property window to see if conversion is needed, and if so, check it.
For example, the project pricing software of Cost 168 has not only coefficient conversion, but also parameter adjustment. As long as the parameter values are entered, the system automatically calculates the consumption, which is more in line with the usage habits of budget personnel.
It is stipulated in the quota specification that when the earthwork is transported and unloaded by truck manually, when the actual distance is greater than 30Km, every increase of 1km in the part exceeding 30km shall be calculated by multiplying the corresponding quota subtitle by a coefficient of 0.65, and special attention shall be paid to this conversion coefficient when applying this quota.
Also, when installing the project, the quota specification stipulates that the power cable laying quota should be considered as three cores (including three-core grounding). The five-core power cable laying quota is multiplied by the coefficient 1.30, and the six-core power cable is multiplied by the coefficient 1.60, and each additional core quota is increased by 30%, and so on. Single-core power cable laying is multiplied by the coefficient of 0.67 according to the cable laying quota of the same section. Single-core power cable laying with a cross section greater than 400mm2 to 800mm2 shall be carried out according to the power cable laying quota of 400mm2. 800 ~ 1000mm2 section. Single-core power cable laying shall be based on 400mm2 power cable laying quota multiplied by the coefficient 1.25. When applying this quota, as long as the core number is directly input in the quota adjustment module, the software will automatically calculate the consumption.
7. Inaccurate material pricing is the most common mistake in project cost.
When pricing directly with pricing software, pay attention to the errors such as different material specifications and design requirements, and large gap between material prices and market inquiry.
5.2.1-7 of the Code for Valuation with Bill of Quantities of Construction Projects (GB 50500-201-7) stipulates: "The tender control price is based on the project cost information released by the project cost management organization; If the project cost information is not released, refer to the market price. And the cost of engineering equipment is included in the material cost, and the inspection and test fee in the raw material cost is included in the enterprise management fee.
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