DRAFT MODEL FOR CREATING A FINANCIAL INDICATORS OF BRIDGE CONSTRUCTION

The paper deals with a problem of developing, defining and applying budgetary indicators of engineering constructions, and particularly bridges. It is a draft of a Model for development of budgetary indicators of bridge construction in the pre-investment phase of a project. It could, according to classification and evaluation in terms of criteria and search for the most accurate valuation unit of complex structures such as bridge construction, serve investors and public administration authorities for rapid investment planning and professional control of completed buildings. Such a unique tool has never been developed in the Czech Republic so far. Bridges as buildings complement any landscape and in the outer parts of cities, they often establish a viewpoint. They belong among important parts of any highway or expressway. Without them, it would be impossible to establish grade-separated crossings with other roads roads, railway lines or sections of rivers. They are also important in overcoming obstacles of natural and artificial character such as deep valleys, lakes, or steep mountainsides. The aim of the paper is to analyse a current state of the valuation of bridges and the subsequent establishment and validation of the Model for the development of budgetary indicators of the bridge construction.


INTRODUCTION "Bridge -an engineering work or a statue?"
Recently, we have been seeing increasingly more signs that construction of Czech highways and roads, and the related construction of highway and road bridges, is more costly both when compared with economically equivalent Central European states and with economically more advanced Western European states.This concerns both construction of new bridges and unsatisfactory condition of already built road and highway bridges.The most widespread opinion is that the current condition of most bridges is unsatisfactory and that it is caused by many factors including above all:  age of the constructions (see D1 highway bridges),  significantly increased and more dynamic load as compared with original assumptions,

Overview of used research methods:
 Analysis and synthesis  Correlation and regression analysis  Descriptive statisticsstatistic classification of datahistogram of frequencies.

Two basic research questions arise in connection with the above-mentioned opinion:
 Why do study results often state a high price for construction of a bridge structure? Do budget indicators from the companies ÚRS PRAHA, a.s. and RTS, a.s.reflect the actual reality?

Summary of the literature connected with the subject of paper:
 Spon´s Civil Engineering and Highway Works Price Book [1]  Stráský, J. (2001).Betonové mosty [2]  Bridge Engineering: Construction and Maintenance [3] Current situation of the issue in the Czech Republic

Main used budget indicators of a construction structure (RUSO)
The basic elements necessary for the first calculation of price of constructions in the preinvestment phase of a construction project are budget indicators.These budget indicators are created by special private organisations in CZR, such as:  ÚRS PRAHA, a.s., [4]  RTS Brno, a.s., [5]  Ředitelství silnic a dálnic ČR (publicly inaccessible on the basis of realised constructions),  IBR Consulting s.r.o.(publicly accessible updated prices for pricing of construction in the phase of DÚR).
Professional literature covering the topic of bridges is mostly technically oriented in the Czech Republic.This refers to the book called "Betonové mosty I / Concrete Bridges I" taking into consideration the relation between technical design and price [6].From among the international sources, particularly German professional literature reports on this topic.[7] Currently, as of 2013 -2014, approximately 17 445 bridges are recorded in the Czech Republic, of which 1 568 are on highways and skyways, 3 286 bridges on I-class roads, 4 516 bridges on IIclass roads and 8 075 bridges on III-class roads [8].

Fig. 1: Classification of bridges according to the type of the road, Source: own elaboration
The following graph shows an overview of bridges on highways and I, II and III-class roads according to the type of the load-bearing structure.The most frequent bridges from the perspective of characteristics of the used material are bridges with concrete load-bearing structure.According to the Czech construction standards, acceptable differences between the calculated and real costs are within the range of + -15%.[9]

Solution procedure
To find a correct solution for the given issue, it is necessary to know bridges from the technical and price point of view.
Item budgets were elaborated by means of the software ASPE on the price level 2013 (basic budget costs without VAT and without costs on placement of the construction) on the basis of project documentation and bill of quantities.It is a software "Automatizovany System Podnikove Ekonomiky" (Automated Corporate Economy System), which is designed for preparation and realisation of constructions and which is used especially for realisation of roads and it is also very important for elaboration of bridge cost calculations.
Random effects related to general constructions and works were removed from item budgets.The price does not include:  Elaboration of a bridge sheet,  testing of material by an independent testing centre,  testing of constructions and works by a testing centre of the contractorpreliminary agreement,  testing of constructions and works by a testing centre of the contractor,  other requirementsland survey measurements,  geodetic surveying,  assessments, inspections, revision reports,  main bridge inspection,  documentation of actual realisation in a digital form.

 disposal site fee
In general, it applies that each bridge is an original with regard to its position, technology and other effects.Therefore, items related to general constructions and works are not used in the proposal of creation of budget indicator.The analysis shows that in the case of bridge constructions, general constructions and works form 4 -5% of the total basic budget costs.The disposal site fee is considered only at the general level in the proposed model.
For a better transparency, a table was elaborated for 13 samples of designed bridges with the load-bearing structure "prefabricated prefa girder".The table shows deviations from the real basic budget costs as compared with costs determined according to the indicator price ÚRS Praha, a.s. and RTS Brno, a.s. on the price level 2013.It includes basic budget costs without VAT and it does not include costs of placement of the construction.On the basis of costs mentioned in Tab. 1 we could say even surprising deviations, which show us the percentage manifestation of the real costs compared with costs according to the indicator price established by the companies ÚRS Praha a.s. and RTS Brno on the price level 2013, it will be necessary to find new budget indicators, to classify the bridges and their material characteristics more precisely and to define the basic evaluation unit.--------------------------------------------------------------------------------------------------------------- Construction material characteristics:  1 monolithic concrete prestressed board structure  2 monolithic concrete prestressed beam structure  3 assembled from parts of prestressed PREFA GIRDER [11] Selection of relevant criteria, defining their variants and creation of the basic representativeprice indicator of the given bridge structure.

Example:
Road bridges, concrete bridges, highway and skyway overpasses, load-bearing structure assembled from parts of prestressed PREFA GIRDER.The anticipated dependency between the variables was discovered by means of the correlation and regression analysis:

Tab. 3: Bridges -PREFA GIRDER, Source: own elaboration
 BBC and amount of the dug-up earth, backfill and embankment (m 3 )  BBC and amount of concrete including bridge supports, wings, cornice (m 3 )  To define variants on the basis of comparative statistics methods, where the occurrence frequency of variants for the proposed relevant criterion was determined. Variants with the most frequent occurrence for each relevant criterion were selected and, on the basis of the method mentioned in the previous step, 3 representatives were defined, which have similar values in their selected criteria.
The representativeprice indicator was selected with basic parameters and resulting averaged guide price for 1m 2 of the area of the load-bearing structure 37 026CZK/m 2 .Values, which are stated in the proposed relevant criteria, were determined by means of arithmetic means with the number in the absolute value.

Selected representative
Indicative price/m 2 CZK37.026per square Amount of digging works 1 001 -5 000m 3 As bridges are also designed in different values than the selected representative, it was necessary to optimise the price of the real or particular bridge with regard to its designed parameters, especially in the following variants, which include the individual relevant criteria.
 Class of rocks higher than III  Amount of digging works to 100m 3 ,101-1000m 3 , over 5000m 3  Foundation difficulty special foundation -2 (boreholes, piles, sheet-pile walls)  Number of fields 1, 3 and more  Area of bridge floor to 300m 2 , 401-600m 2 , 601-900m 2 , over 901m 2 The newly proposed indicators of an average guide price (budget price) were related to the measuring unit m 2 in the following table on the basis of the above-mentioned methodology for creation of a representative of a bridge structure.
Tab. 4  Results from the suggested methodology for "Road bridges -Concrete bridges" are the basis for a model for creation of budget indicators of a bridge structure.

CONCLUSION
The resulting model will enable simple specifying of investment costs for construction of new concrete bridges as civil structures (i.e.highway and road bridges, including highway and motorway flyovers).It may be used in the pre-investment phase allowing fast and specifically exact pricing of planned investment.Investors and/or designers may use it as well as other professionals.
There are 17.445 bridges of different age in the Czech Republic.Determining construction costs of their repair, maintenance, or modernisation will be topic of the day in the upcoming years (due to the life expectancy of for instance bridge floor insulation, as it is around 20 years).This is why the Model will be designed allowing adding more modules.
 Module OCsteel-concrete bridges. Module PKbackfilled structuresbio-corridors.  Module OUrepair and maintenance of bridges. Module RE -modernisation of a bridge. Module RMconstruction of railway bridges, industrial, water-management corridors, and pedestrian bridges.
It must be considered that investment costs defined by the model do not contain related costs unsubstantiated in the database of directional costs, and these are first of all:  cost of project documents,  cost of geodetic survey,  testing of structures and work by contractor's test labpreliminary,  testing of structures and work by contractor's test lab,  other requirementsgeodetic surveying, expert opinions, check-ups, revision reports,  key bridge inspection,  digital as-built documents,  VRN (NUS) / additional budgeted cost (site-related costs),  VAT.
On the other hand, the market environment (contractors' interest to build) sometimes pushes investor costs down by as much as 20-30 per cent compared to directional costs specified in the Model.Yet the Model is structured in such a manner so that the basic entry data could be updated and still maintain costs relative to affecting parameters.

ABBREVIATIONS
ÚRS PRAHA, a.s.-the successor to the oldest organisation of this type in the Czech Republic that was the state-owned Ústav pro racionalizaci ve stavebnictví / Institute for Rationalization in Construction Engineering liquidated at the beginning of the 1990s.

Fig. 2 :
Fig. 2: Overview of bridges according to the type of the load-bearing structure, Source: own elaboration Predominance of bridges with concrete load-bearing structure is one of the main reasons for focus of this work.

Proposal of a new
classification for concrete bridges, which is based on general classification of bridges:  According to the type of transport: o road bridges. According to the type of obstacle (from the perspective of the bridge project): o highway and skyway overpasses, o highway and road bridges, o embanked bridges, o single-span bridges, o urban viaducts, o bridges across rivers, o bridges across deep valleys, o pedestrian bridges.THE CIVIL ENGINEERING JOURNAL 1-2015 -

concrete in m 3 (
Bridge supports, wings and cornices, ŽL class,

Bridge name Bridge parameters (m, m, m, m, m 2 ) BBC without VAT and CPC in PL 2013
Guide price indicators related to m 2 , Source: own elaboration