1 expressway reconstruction and expansion project method
In the highway reconstruction and expansion project, people have accumulated a variety of methods, which should be reasonably selected according to specific needs in practical work. The main methods are as follows.
1. 1 bilateral widening method
This way of expanding plains and gentle slopes has the advantages of less land occupation, simple construction and less investment, but it has a great impact on traffic.
1.2 unilateral widening method
Due to the limitation of terrain, the unilateral widening method is insensitive to differential settlement of subgrade, and the construction organization is easy, which has little influence on vehicle traffic, but the cost is high.
1.3 new highway construction method
The mountainous and hilly areas can't be widened due to terrain restrictions, so new roads should be built. If the improvement of the old road and the use of the interchange are not considered, the cost is the same as that of the new road [1].
2 characteristics of highway reconstruction and expansion project cost compilation
The compilation of reconstruction and expansion project cost has its remarkable characteristics. We should not only consider the construction cost of new projects, but also grasp the cost of other projects, so as to make a more reasonable cost budget.
2. 1 service road construction fee
In order to ensure the normal traffic of the old road, the through service road is calculated on both sides, and one side can be widened.
2.2 Borrowing soil filling fee
Do a good job of soil field investigation along the line, reasonably determine the location of the soil field, and test the nature of the soil to ensure that it meets the requirements. According to the borrowing distance, freight, borrowing resources and other reasonable fees.
2.3 soft foundation treatment fee
After the roadbed is widened, uneven settlement may occur, which will bring damage to the roadbed. The widening project needs to deal with special subgrade, which is costly.
2.4 Traffic interference fee
In order to ensure the integrity and aesthetics of the pavement, the new and old subgrade of the upper layer should be paved at the same time, and some traffic interference fees should be considered.
2.5 Guarantee measures fee
During the construction period, traffic shall not be interrupted, and the line operation capacity and service level shall not be reduced. Measures to ensure traffic safety are particularly important and cannot be ignored when compiling expenses. Formulate an effective guarantee scheme and cost structure. According to the previous experience of reconstruction and expansion, the width of both sides is calculated at 700,000-800,000 yuan /km, and the width of one side is calculated at 300,000-500,000 yuan /km.
2.6 environmental protection measures fee
The cost of garbage disposal, relocation and recycling of pavement, subgrade, overpass, waterproof and drainage works, etc. [2], in the cost preparation can not be ignored.
3 expressway reconstruction and expansion project of new technology unit price calculation
The reconstruction and expansion project is carried out on the basis of the original expressway, so in addition to the cost of preparing new projects, We should also consider the cost of new technology and pay attention to the calculation of unit price of new technology, which mainly includes the following contents.
3. 1 Connection treatment of new and old subgrade
The widened road and the original road form a whole, so we must pay attention to the combination of old and new subgrade to improve the engineering quality. The old subgrade has been running for many years, and the subgrade settlement is formed and relatively stable. In order to connect the new subgrade with the old subgrade, the common treatment methods are digging steps on the old roadside slope, laying geogrids, impact rolling before filling the new subgrade, and deep treatment of CFG piles and powder injection piles. This part of the cost should be considered comprehensively when compiling the cost. Usually, it is easy to ignore the cost of digging steps and laying geogrids on old roads in the cost estimation stage. The cost of soft foundation treatment should be comprehensively considered in combination with the length of the route, and the provisions revised in 2007 can be adopted in the budget estimate quota. So as to improve the rationality of cost preparation and better guide the project construction.
3.2 Lapping treatment of old and new bridges
In order to make the new bridge and the old bridge form a whole and bear the same force without changing the original stress of the old bridge, the bridge widening methods are usually the same structure, the same span, "upper connection" and "lower disconnection". The method of "upper connection" is to connect the upper hollow slab structure by wet connection, remove the external wall guardrail of the old bridge by vibration-free cutting technology, plant connectors on the outer plate of the old bridge, lap it with the embedded parts of the new plate, pour joints, and lay concrete on the bridge deck to complete the upper transverse connection of the old and new bridges. "No connection under" means that a joint of 1cm is set between the new and old capping beams at the lower part without any connection. This overlapping processing method brings difficulties to cost compilation. Not only is there no quota set, but there is no empirical data reference. According to the reconstruction project of Zhengzhou section of Lianhuo Expressway, the unit price of the following new technologies is calculated. Such as reinforced concrete guardrail 1300 yuan /m2, reinforced concrete capping beam 1500 yuan /m2, φ 12 rebar 15 yuan/root, φ 16 rebar 20 yuan/root, and A3 steel plate 1300 yuan /m2. It can be used as a reference for compiling the overlapping treatment cost of old and new bridges.
3.3 Disease Treatment of Old Roads and Bridges
Generally, the operation time for the reconstruction and expansion of expressway is more than 10 years. In order to make the new and old roads at the same service level after expansion, the disease treatment of the old road bridges can not be ignored. In the treatment of old road diseases, the key content is to detect diseases and master the position of diseases. Rational use of waste materials, pay attention to cold recycling and hot recycling of asphalt mixture. According to various consultations, combined with design and construction experience, the unit price of new asphalt recycling process is as follows: milling 80 yuan /m3, adding 2% foamed asphalt 175 yuan /m3, adding 15% new material 120 yuan /m3, construction cost 125 yuan /m3, and the comprehensive unit price is 5 yuan/m3. The milling and planing of the old road, the transportation and paving of the mixture can be calculated according to the quota, and the processing fee of the new road paving mixture can be calculated according to the additive and equipment shift fee. At present, there is no accurate quota for the cost calculation of old bridge reinforcement and repair, and it is generally calculated according to the engineering practice. The unit price of common new technologies is as follows: 80 yuan/m for removing the original bridge expansion joint; When the old hollow slab is demolished for 20m and the transportation distance is 3km, the unit price is 2600 yuan; Demolition of the old hollow slab 16m, when the transportation distance is 3km, the unit price is 1800 yuan; 700 yuan/m2 of cracks in superstructure treated with carbon fiber sheet; 30 yuan/m of epoxy mortar for treating lower non-structural cracks; Epoxy concrete treatment of pits and exposed tendons 160 yuan/m2; Thickness of hinged reinforced steel plate 19mm, price 1300 yuan /m2. This should be used as a reference for cost calculation.
3.4 Demolition of Drainage and Waterproofing Works
Road widening often needs to dismantle the waterproof and drainage works of old roads, and waste treatment is one of the important tasks. Making full use of waste is conducive to reducing costs. Therefore, the cost personnel should strengthen communication with the designers, understand the design intent, make a scientific and reasonable plan and make an accurate evaluation. The amount of demolition work can be estimated, but there is no special index. Apply budgetary estimate quota, rationally use and allocate waste materials, and promote them to exert maximum benefits. And do a good job in the drainage and waterproof construction of new roads to save costs.
3.5 Overpass and Overpass Treatment
Simply supported beam bridges are usually lengthened at both ends of the original bridge to ensure that the widened bridge meets the requirements of road width, and bridges such as continuous beams, T-shaped steel structures and inclined leg steel structures should be demolished. In the process of demolition, it is necessary to ensure uninterrupted traffic, prevent damage to the road surface in expressway and ensure the safe passage of vehicles. Generally, one-way release, one-way temporary support and full-house support are set, concrete is cut and removed, waste materials are transported away in time, and traffic is diverted in time [4]. In order to reduce the impact on traffic and save the cost, it is unreasonable to calculate the cost by applying the quota according to the conventional method. Through calculation and negotiation, the unit price of demolition is about 1 150 ~ 1500 yuan /m2. In the concrete calculation, the structural forms of overpasses and overpasses, local topographic conditions and other factors should be considered to improve the rationality of cost compilation.
3.6 Reconstruction cost of facilities along the line
When compiling the cost, the most difficult thing is to determine the demolition cost of guardrails, signs and markings and emergency telephone booths along the line. According to the completed reconstruction and expansion project, the cost of dismantling facilities along the line is as follows: 500 yuan, a sound barrier, 280 yuan, a single-column road traffic sign, 950 yuan, a double-column cantilever 430 yuan, a gantry 1.600 yuan, a telephone booth, 300 yuan, and 25 yuan, a corrugated steel guardrail. In addition, the recovery of safety facilities is also a work that cannot be ignored. According to the length of the line, the budget is made according to the budgeting method, and new standards are implemented to improve the rationality of cost estimation. The original safety facilities can be used, and those that cannot be used can be recycled as much as possible to save costs.
4 conclusion
(1) Bilateral widening is the most economical scheme. There are many factors that affect the cost of widening project, and the cost compilation is also complicated and expensive. The cost of three schemes of bilateral widening, unilateral widening and new highway is compared and analyzed, in which bilateral widening is the most economical scheme. Compared with unilateral widening, it can save about 2.6 million yuan per kilometer, so we should pay attention to the application of bilateral widening scheme in reconstruction and expansion projects. (2) Increase the design depth of the reconstruction and expansion project. Compared with the newly-built expressway project, the cost compilation of the reconstruction and expansion project is quite different, and there are few applicable indicators. It is easy to miss items and underestimate, which also affects the budget estimate and budget in the next stage, and it is difficult to fully reflect the investment scale. Therefore, in order to deal with this situation, we should increase the design depth, fully grasp the actual situation of the project, improve the scientific and reasonable cost preparation, and better guide the project construction. (3) Conduct comprehensive and meticulous cost preparation. In the preliminary design and construction drawing design stage of the reconstruction and expansion project, the cost personnel should fully understand the actual situation of the project in strict accordance with the relevant norms and standards, and formulate a scientific reconstruction and expansion implementation plan. And comprehensively and carefully compile the cost of the reconstruction and expansion project, and compile detailed and reasonable cost documents to better guide the construction of the reconstruction and expansion project.
I believe that after the above introduction, everyone has a certain understanding of the cost budget and preparation of expressway's reconstruction and expansion. Welcome to Zhong Da for more information.
For more information about project/service/procurement bidding, and to improve the winning rate, please click on the bottom of official website Customer Service for free consultation:/#/? source=bdzd