j. kubica, z. paj^k, w. starosolski, j. glqbik · 2014. 5. 20. · j. kubica, z. paj^k, w....

Reconstruction of the Kalwaryjski church

tower without disassembling the 17.0 m high

timber spire

J. Kubica, Z. Paĵ k, W. Starosolski, J. GlqbikDepartment of Building Structures, Silesian University of Technology,PL-44-100 Gliwice, ul Akademicka 5, PolandEMail: jkub@katkon. bud.polsl gliwice.pl

Abstract

The paper deals the problems connected with restoration of one of the mostfamous and important pilgrim churches in Poland. The masonry tower of the 100year old Kalwaryjski Church in Piekary Sl̂ skie (Upper Silesia) has failed, withthe indoor and outdoor damages and destructions as a result of influences ofaggressive mediums. The most dangerous damages were observed in the upperpart of the tower. This part was practically completely devastated. The method ofrestoration of this tower is shown. The most affected upper part (ca. 8.0 m high)of the clay brick masonry tower walls was replaced with the new structurewithout the necessity of disassembling the 17.0 m high timber spire on top of thetower. In order to enable the replacement of the upper part of the tower, a steelframe construction was applied. An additional aspect of the methods ofrestoration used was permitting the reconstruction of the primary form of theupper part of tower and allowing the use of the tower bells.

1 Introduction

Old historical, monumental buildings, also made of clay brick masonry, duringthe long term of exploitation, as a result of influences of many different factors,like humidity, temperature and chemical aggression, were subjected to graduallyaccrued damages. These damages, if they were not suitably repaired, becamelarger and more dangerous. Finally, they could lead to a limiting state in someparts of the load bearing structure, or even whole buildings. Sometimes, as an

Transactions on the Built Environment vol 39 © 1999 WIT Press, www.witpress.com, ISSN 1743-3509

688 Structural Studies, Repairs and Maintenance of Historical Buildings

effect of situation like that, the catastrophe of building is observed. In paper anexample of strongly damaged, practically in failure state, construction of claybrick masonry bell tower of 100 years old Kalwaryjski Church in Upper Silesiawas presented. The damages with analysis of reasons of their appearance andapplied method of restoration, were described.

2 Construction of the tower

The Kalwaryjski Church building, which overall view in Fig.l has shown waserected between 1862 and 1896 on the top of the Cerekwica Hill in PiekarySlaskie (in north-west part of Upper Silesia Industrial Region) according toproject of architect Wladystaw Schneider

Figure 1: General view of front facade of the Kalwaryjski Churchin Piekary Sl̂ skie.


Structural Studies, Repairs and Maintenance of Historical Buildings 689

The whole church was built by city-dwellers of Piekary Sl#ie. The total high ofthe clay brick masonry bell tower (see Fig.2) is about 50,0 m.

A-A

B-B

C-C

Figure 2: Shape and overall dimensions of bell tower and theirhorizontal projections on three main levels.



In their lower part, the tower has a tetragonal section with 5,9 m length sides andis connected with masonry walls of central nave of building and aisles.Thickness of walls in lower part of the tower is 1,35 m. There are 8 pilasters inthe corners of the tower. In each corner are 2 pilasters (see section C-C in Fig.2).The width of pilaster is 0,65 m, but their high is not a constant value. It'schanging on 4 levels, from 1,2 m in lower part up to 0,8 m in the upper part ofthe tower. From level +25,80 m up to +32,40 m the horizontal section of towerhas 8 sides. Each of them according to principal design solution had an openingbut very earlier 4 of these openings were closed using 0,38 m thick masonry.Probably, with 8 openings the stiffness of this upper part of tower was too low.In some places of the internal side of the tower columns between windowopenings, old cracks under plaster were observed. That is providing that safety ofconstruction of the tower was menaced.The tower is closed by 17,0 m high timber spire. Whole spire is covered withzinc coated sheets. There are 4 floors inside the tower. These floors are situatedat following levels: +11,40 m, +15,90 m (bell floor), +20,83 m (clock floor) and+24,58 m (part of tower with openings). Construction of each of these floors wassimilar: reinforced concrete plate supported on steel beams with anchorage inmasonry load bearing walls of the tower.

3 Description and analysis of observed damages

During a long period of exploitation many different types of damages, like:

• large damp areas of external masonry walls, including pilasters andbuttresses. The traces of dampness', changes of the colour of the bricks andmortars and salt efflorescence were observed on internal and externalsurfaces of walls;

# irregular cracks visible in external brickwork and some large cracks acrossthe whole thickness of the wall, especially along the contact line of wallswith pilasters and buttresses;

* spalling of bricks and mortars in surfaces of facades conducted to falling outbricks of walls;

• lixiviations, sulphate attack and cracks of a lot of decorative elements madeof concrete;

was experienced.

All types of damages, given above, were observed on whole facade of thechurch. The most intensive damages were appeared in upper part of the tower.Most of masonry pilasters, especially on west side of the tower was verticallycracked with slack bricks at any moment could be falling down. Safety of thispart of the building was menaced. Immediately there were temporary protected(Fig.3) using timber boards and steel bars. Additionally, these parts of tower



were covered with plastics net. For fear of further damages, the tower bells wereimmobilised.

Figure 3: View of temporary protected, strongly damaged pillarsin upper part of the tower.

Vertical cracks and other types of damages could be the result of the influence ofmany different factors [1,2]. The main reason of observed damages of the tower



construction, was the influence of chemical aggressive medium of atmosphere inUpper Silesia and frost bursting. The additional factors accelerating processes ofdestruction of building analysed, were:

• air pollution of chemical aggressive industrial gases and dusts. Upper Silesiais the most intensive industrial region in Poland. From many hundreds yearsa lot of heavy industry factories produced many toxic and aggressivecompounds, like acid rains;

• location of church on the top of the hill;

• complicated and very "reach" architecture form of body of the building;

• using for brickwork's a low quality clay bricks and lime mortar of lowmechanics parameters;

• wrong earlier repair works. In the past, for the repair works of the damagedbrickwork's of the external facades, the completely inadequate mortars (verystrong cement mortars) were used. Moreover, whole surface of the fagadewas emulsion painted;

• destructive action of corroded steel elements built-in the brickwork;

• wrong construction of water draining elements, especially in lower part ofthe timber spire,

4 Method of restoration

A very bad technical state of the brickwork connected with quickly occurrenceof damages, especially during last a few years, required to start immediately withcomplex renovation of tower and in consequence, whole building. The mostdifficult problem, both in respect of construction solution and adequatetechnology, was the method of restoration of strongly damaged, upper part of themasonry bell tower. There are no so much indicates in that's matter in Polishprofessional literature (e.g. in [3]). The primary calculations and analysis madeby building experts were indicated to necessity of disassembling (up to +26,0 mlevel) of the 17,0 m high construction of timber spire, crowned the tower. Thissolution has two main negative aspects:

* needs using of a heavy crane with capacity not less than 40 tons andlong crane lib;

• cost of disassembling of the old spire and making of a new one is toohigh and not possibly to acceptance for owner of the church.

Therefore, authors were proposed the restoration of masonry walls of upper partof the tower without necessity of timber spire disassembling. Elements ofconstruction of this spire were generally in good condition, except zones ofsupporting in the lower part. Only the ends of the main timber beams, insidemasonry walls, were intensive damaged and required the repair works.



In presented method, the execution of spatial steel frame construction inside thetower, was proposed. It was made an assumption, that steel structure will be bothmontage supporting of the timber spire and stiffening of pillars betweenopenings in further exploitation of the building. The acceptance of presentedmethod, permitted to open all 8 openings, like in primary design solution.The idea of proposed solution of strengthening of upper part of masonry wallsand scheme of steel frame construction, has shown in Fig.4. There was nomarked all truss bracings of the steel frames on this Figure. In reality, they werein all surfaces of the space frame.

a) b)

+ 149.40

Figure 4: Scheme of proposed solution (a) and scheme of steelframe construction (b).



Construction of space frame (designated on Fig.4 as "1") was adapted togeometrical conditions of interior of the tower. The spaces of all 8 openings werenot screening off. Conditions of realisation of presented steel strengtheningstructures were required limits in relation to the maximal length and weight ofsteel elements. All these elements were no longer than 3,0 m and not exceedweight about 2 kN. The bold joints were used. Steel frame, made as the spacecolumn (2,12 m width and about 7,0 m high) was composed with two verticalplane trusses connected to each other by horizontal and diagonal steel rollingprofiles. Special steel strut constructions were welded on the top of the upperhorizontal beams of the structure. The task of these constructions was to transferthe ftical loads from spire to the masonry walls of the tower after theirrenovation. On first and second level of the steel space frame the flexible wireelements of anchorage of new brickwork's were used. The base of the spaceframe was anchored in reinforced concrete plates (designated on Fig.4 as "2")made on the top of the existing floor on +24,85 m level. Whole constructionswere additionally anchored in the floor of the lower level with vertical steelwires (elements "3" on Fig.4). After mounting steel space frame was started totake to the pieces the damaged part of the tower. Fig.5 shows the detail of thesupporting of lower part of timber spire on the steel structure, but Fig.6 shows ageneral view of the upper part of the tower during exchanging of the brickwork.

Figure 5: Detail of the supporting of lower part of the timber spireon the steel structure.

During restoration works the completely damaged timber elements of lower partof the spire were also changed. Additionally the anchorages in masonry walls ofthese elements were strengthened with steel clamping rings. All timber elementswere cleaned and protected. To the repair works were used clinker bricks and



plastic cement mortar. The characteristic compressive strength of mortar (tested)was about 14,0 N/nnn̂ . Now most of the repair works, especially restoration ofthe church tower, was finished.

Figure 6: View of upper part of the tower during brickwork exchanging.

Besides the reconstruction of the most damaged part of tower also repairing ofthe other part of the tower and a main building body was recommended. Themost important of these works were:



• strengthening of the connections of pillars and buttresses with externalmasonry walls. The basic solution, well known from professional literature(e.g. from [4]), was to remove and replace shaded cracked blocks with newand fill the cracks an appropriate (commonly 1:1:6) mortar mix, wellrammed in, and repoint the surface. When the cracks were large,additionally the expansion bolts of modified mortar fixings were used;

• renovation and restoration of whole facade surface and externalarchitectonic details of tower. First the fagade surface was cleaned and thanthe gaps was filled with suitable mortar mix.

5 Summary

Presented method of restoration was permitted to replace the 8,0 m high upperpart of tower without necessity of disassembling of the 17,0 m high, timber spirecrowned the top of the tower. Choice of this method was connected with somepositive aspects, like:

• short period of restoration works;

• lack of necessity of using a heavy crane and other equipment's;

• additionally strengthening and stiffening of the whole upper part of thetower;

• approach like presented distinctly reduced the total cost of wholerestoration.

Moreover as an additional aspect of used method of restoration was permitting toreconstruction the primary design form of upper part of tower (window openinginto each wall) and admitting to use the tower bells. The authors were thinkingthat presented method could be also successfully use in other similar cases.

References

1. Mitzel, A., Stachurski, W. & Suwalski, Damages of RC and MasonryStructures (in Polish). ARKADY Publishing, 2̂ Edition, Warsaw,1982.

2. Freeman, T.J., Littlejohn, G.S. & Driscoll R.M.C., Has your house gotCracks? A guide to subsidence and heave on buildings on clay.Thomas Telford Services Ltd, London, 1994.

3. Thiery, J. & Zaleski, S., Repairs and strengthening of structures (inPolish). ARKADY Publishing, 3̂ Edition, Warsaw, 1982.

4. Parkinson, G., Shaw, G., Beck, J.K. & Knowles, D., Appraisal &Repair of Masonry. Thomas Telford Services Ltd, London, 1996.


j. kubica, z. paj^k, w. starosolski, j. glqbik · 2014. 5. 20. · j. kubica, z. paj^k, w....

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