The bed up (to the water) and

The major underwater inspection is to
evaluate all below water bridge elements (Fig. 2.2.2.2.) in order to check
their functionality. The riverbed near the bridge should also be checked. Also,
to be determined necessary maintenance work and their costs. 1; 12

Fig. 2.2.2.2. All below water bridge elements
and river bed 53

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This inspection includes a riverbed check and underwater check the basics
to make sure they are in perfect order. The need for sampling from the river bed
should also be considered, to check the constant presence of rust. It may be
necessary to carry out more extensive measurements and material tests when a
major underwater inspection revealed a major need after repair or information
obtained is not sufficient to decide what the type of damage, the degree, the
consequences, the prevalence and the cause. 1; 12

Inspection must be carried out by qualified
divers with appropriate regulations permission. The visual inspection must be close to the type, i.e.,
the diving must be able to touch verifiable bridge elements.

Before visual inspection, the bases must be
cleaned of molds and growth on so in a big area to get a clear overview based
on the situation. Anti-corrosion protection is not required to remove. Also,
anti-skid cladding should not be removed. Growth on should be removed by
pulling it off with a spade and / or high-pressure water jet. Any damage should
be recorded based on the layout drawing. The basics should be checked from the
river bed up (to the water) and including a variable (main?gais ?densl?menis)
water level zone. Every damage should be carefully described and photographed. 1;
12

1.1.1.  An Additional/Special
Inspection

The purpose of the Special
Inspection is to investigate in more detail damages noted in previous
inspections, the causes of damage occurrence and preparation a description of
the costly and/or complex of the planned measures. 1; 12

Special inspections are not carried out on a
regular basis, but they are planned in accordance with the following
considerations:

·        
Requirements for previous major inspections;

·        
Accidents, such as car damage;

·        
Overload;

·        
Flooding;

·        
Previous experience with similar bridge types and
environmental factors. 1;12

This inspection is conducted to monitor a single known defect or condition.

 

1.2.   Damage Evaluation

Common defects in concrete bridge materials are cracks, scaling, leveling,
spooling, leak, honey, curvature, wear, collision damage, overload damage, reinforced
steel corrosion and tension concrete damage.

In most cases, damage assessment is a visual assessment, which is sometimes
followed by measurements and material checks.

However, it may be necessary to calculate in some special cases the
carrying capacity of the structures and make economic analysis as well as carry
out bridge long-term instrumental observation to obtain reliable information
and correct damage evaluation. 1; 13

When evaluating the damage to the bridge, it must be determined:

·      
damage type;

·        
damage consequences on the bridge;

·      
cause of damage.

In LatBrutus each damage type is
given with a three-digit code; the first digit indicates material or element,
but the second and third one’s digit – for damage type. This is done to
simplify the damage registration in the database and allow data to be read for
processing and for analysis. Typical bridge damages are to the substrate
(pamatnes) (damage to the river bed and damage to the protective equipment),
concrete elements, steel elements, stone / masonry elements, wooden elements,
deck damages, lesions of bone / joint (balst?klu/šuvju) and damages to
drainage, access and equipment. 1

The degree of damage is used to indicate the severity of a fault depends on
the speed of its development, and the severity of the inspections for each
individual damage or injury group.

Bridging inspections can produce photos, bridge dimensions, bridge heights
and bridge coordinates.

 

1.3.   Bridge inspection practices in other
countries.

Bridge inspection practices display changes from country to country
according to social, economic, political or even climatic and geographical
reasons. However, because of the need to rate bridges under the federally
authorized bridge inspection programs to ensure eligibility under federal
funding, state agencies have attempted to standardize procedures for evaluating
the consequences of deterioration. 14

In Finland simple safety inspections are conducted annually. Primary
inspections occur every five years, as do underwater inspections, if
applicable. More frequent inspections occur for bridges in poor condition or
for important bridges. 15

In Sweden major inspections are performed every six years, and are arm’s
length inspections. A decision about the inspection interval is made after the
major inspection, and deteriorating bridges are inspected more frequently. A
general inspection is a follow-up inspection for the major inspection, and
occurs in the interval between major inspections. 15

In Germany Basic inspections are performed by maintenance personnel and
occur at frequent but undefined intervals. Visual inspections occur every three
years, and major inspections involving material testing and an in-depth visual
inspection occur every six years. 15

 

 

 

 

1.4.   Existing problems in bridge visual
inspections

 

The eye is a powerful test
tool, mainly because it is connected to the human brain, which has information
and skills that have no mechanism have. However, the eye may be false (2.5.1.
Fig), knowing its limitations are important.

2.5.1. Fig. Optical illusion: parallel lines made from black and white
pillows 39

As shown in Fig. 2.1.5., above, the eye is not the most accurate and
reliable instrument, but that does not mean that visual inspections are always
unreliable, although they should not be your only method of
inspection.

Also, inspections depend mainly on the subjective evaluations made by
bridge inspectors which in turn rely on experience, engineering judgment and
visual acuity of the inspector.

It is time consuming task which also require a significant amount of time
for analyzing and interpreting the collected data. 38

Therefore, taking into account the modern possibilities, it is necessary to
use all the modern advantages of the present – electronic measuring devices
with which it is possible to automatically measure the sizes and surfaces and
which data can then be processed and the results can be interpreted more
automatically. An example of a laser scanner from which you can get a point
cloud (2.5.2.Fig.) that can be transformed into a 3d model and analyzed, and
shape forecast models later.

 

 

2.5.2.     
Fig. Bridge point cloud 40

Therefore, taking into account all the above, it is very important to
quickly and efficiently manage the data obtained during bridge inspections.
Therefore, the next chapters will cover what kind of geospatial data exists and
what kind of geospatial data can be produced in bridge inspections.

And after that will be described the existing Latvian construction
information system, which in future could have a module for bridges and their
inspections, which seems an effective and logical step to save money on
maintenance.