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New Integrated Knowledge based approachs to the protection of cultural heritage from Earthquake-induced Risk
Projects


Jerusalem
The Western Wall Tunnels
Removing Hazards from the Hall with the Temple Mount Model
OrdererWestern Wall Heritage Foundation
DurationApril 2006 - October 2009
Implemented by: Evgeny Ivanovsky
Aliza Van Zaiden
'Attoun Hader
Yossi Vaknin
Eetai Abksis
Shiran Sabag
Ariel Yogev
Yoni Tirosh HaCohen
Hader Shchada
Tsagai Asma'in
Amit Rosenblum

 
The hall where the Temple Mount model is situated lies in the heart of the Western Wall tunnel complex, which extends from the Western Wall northward, beneath the Muslim Quarter in the Old City. The hall serves today as an important junction in the tunnel complex. Every day hundreds, and sometimes thousands, of people pass through it.  Most of them linger in the vicinity of the model, look at it and listen to an explanation about the tunnel complex and the Old City.
 
The aim of the project was to stabilize the original building elements in order that the hall would be safe to use, without endangering the visitors in it.
 
The hall was built during the Mamluk period and it was the foundation level of the structure that housed the Baladiye Madrasah. This building was used as a school and consisted of four main rooms. A different stream of Sunni Islam was taught in each of the madrasah’s rooms. The madrasah was also called Manqlibua'a al-Ahmadi and Beit Miryam.
 
In the second half of the 20th century the population in the Muslim Quarter increased, which in turn resulted in rapid urban development. Over time the hall was forgotten and building additions in the madrasah’s courtyard caused structural deformations in the vaults of the hall. A sewer pipe was installed inside its pillars which led to destruction and accelerated weathering. Everyday there are many visitors in the subterranean hall beneath the upper level, which bustles with activity.
 
The eastern vault of the hall adjoins the Western Wall. For many of the Jewish visitors this location adds a religious-spiritual touch to the hall. Future development plans include the construction of a synagogue there.
 
Historical - Archaeological Description
The madrasah was erected inside an enormous water reservoir during the Mamluk period (1260-1517 CE). The hall is built of pointed barrel vaults that combine to form a cross-shaped structure. As previously noted, it was built as an underground foundation for the Baladiye Madrasah. The hall has no door or window openings that can attest to any sort of use of the space.

 
The construction of the madrasah is just one component of the urban development that extends west of the Temple Mount to Ha-Gai Street. This development reflects the desire of the Mamluk rulers to enhance their status amongst the Muslim residents. This construction augmented the sanctity of the Temple Mount and created an everyday connection with the sacred focal point – the mosque – that is located on the mount.
 
Elevating the residential region was made possible thanks to the construction of the foundation vaults. These were sometimes utilized as cisterns but in many instances they were not used at all.
 
The first archaeological research was carried out there by Dan Bahat in 1986, with the participation of the Ministry of Religious Affairs. Large amounts of soil debris were removed during the course of an intensive excavation. Upon revealing the cross-shaped outline of the hall it was suggested that this is a Crusader church similar to the church on the Mount of Joy (Montis Gaudii). This hypothesis was negated because, as mentioned above, there was no evidence that indicated the hall was ever used.
 
The most important remains that were exposed in the hall were pottery vessels that date to the Mamluk period and layers of plaster belonging to cisterns from earlier periods. Evidence of a cistern that dates to the time of the Second Temple period was noted in the southwestern corner of the hall. This cistern was probably part of the system that supplied water to the ritual baths that were exposed near the hall.
 
A small scale excavation was conducted in 2008 under the direction of A. Solomon, in cooperation with the Western Wall Heritage Foundation. In this excavation the foundations of the hall where the Temple Mount model is located and the bottom of the Byzantine cistern were examined. The excavation findings showed that the hall’s foundation and the bottom of the Byzantine cistern are located at a depth of c. 4 meters and c. 8 meters respectively below the modern floor level.
 
In reviewing the plans of the different levels we found that the hall was used as the foundation of the Baladiye structure.
 
Architectural and Technological Description
The walls of the hall were built of relatively large stones (0.50-0.75 x 0.80 m) characterized by drafted margins and a coarse prominent boss in the center of the stone. This method of stone dressing is typical of the Ayyubid period, which preceded the Mamluk period. It can therefore be assumed that the Mamluk builders made secondary use of ancient masonry stones.

 
The vaults of the hall were built on a wooden form. Mortar was applied to the form into which small and medium size fieldstones were placed. The back of the vault was poured debesh that contained soil, small fieldstones and a relatively small percentage of lime-based mortar.
 
Evidence of an enormous cistern that dates to the Byzantine period was found in the corners of the hall. The eastern part of the cistern adjoined the Western Wall of the Temple Mount. Small niches were hewn in the Temple Mount’s stones in order to connect the Western Wall with the wall of the cistern. Stone beams were inserted half in the niches and their other half was attached to the wall of the cistern. The wall was made of two layers of plaster and was c. 20-30 centimeters thick. The mortar used in the cistern contained numerous fragments of pottery vessels that facilitated dating the time of the installation’s construction.
 
The Cultural Significance of the Hall
Historical-Technological Aspect

Mamluk Construction. The hall with the Temple Mount model is a complete unit of a relatively large cross-vaulted structure from the Mamluk period. The vaults, despite their problematic constructive condition, were well preserved and reflect the building technology that was employed during the Mamluk period.
 
The Byzantine Cistern. In the cistern’s remains we clearly discerned the technique by which the Byzantine builders attached the installation’s eastern wall to the western wall of the Temple Mount (the Western Wall). This was accomplished by creating niches, utilizing stone beams and applying two thick layers of plaster.
 
Master Course”. The eastern vault of the hall adjoins the Western Wall where the “Master Course”, which is the largest course in the Western Wall, is located and is characterized by construction that utilizes enormous stones. The stones in the course reach a height of c. 3.3 meters, with an estimated depth that ranges from 3.5-4.6 meters. The largest of the stones in the course is c. 13.6 meters in length followed by a stone that is 12.05 meters long. It is thought that the “Master Course” was built in order to support an inner vault. This course of stone is a unique element in the construction of the Temple Mount.
 
Spiritual-Religious Aspect.
While most visitors come to the Western Wall via the Western Wall plaza, a visit to the hall allows one access to the less familiar stone courses of the Western Wall inside the tunnels. The spiritual experience is intensified thanks to the “Master Course”. Visitors are very impressed by the strength and enormity of the stones in the Western Wall, which enhances the religious significance of the place.

 
Tourism Aspect
The Western Wall tunnel complex is filled to capacity with visitors almost every day. The walking paths the visitors take in the tunnel complex pass through the hall so that all visitors to the Western Wall tunnels go through it. The hall is therefore one of the most important stations when visiting the Western Wall Tunnel complex. This fact requires that the safety of the hall be of utmost importance and that aesthetic aspects be strictly adhered to when implementing the conservation work.

 
A model of the Temple Mount and the tunnel complex is located in the western vault. Most visitors linger there. Another important stop in the tunnel complex is opposite the “Master Course” in the eastern vault.
 
Conservation Issues
Several problems were identified inside the hall, which were caused by the following factors:
A. Repeated Leakage along the Inner Surfaces of the Hall. The source of the leakage is connected to the topography. The hall is located at a relatively low point, at the confluence of two streams: the Tyropoeon and the Arav. However, there is also a localized factor contributing to this problem and that is the sewer systems of the upper houses in the quarter.
As a result of this several of the major problems in the hall were created:
1) The fill above the vault was washed away and numerous cavities were formed behind the vault. These cavities cause structural problems that were produced due to changes in the loads exerted on the vaults and their directions.
2) Most of the water flowing into the hall is effluent or sewage, which contains a high percentage of chlorides and nitrates. These chemicals cause salts to crystallize on the surface of the building stones, accelerate the destructive processes and weaken the fabric of the stones. As a result, the strength of the vault is undermined.
3)  The leaking water in the hall detracts from the experience of visiting the site.

 
B. Previous Interventions. In the 1980’s a layer of imitation stone was applied to the surface of the vaults. This layer did not solve the problem of percolating sewage and even exacerbated the state of preservation of the stones in the vault. This layer was is an advanced state of deterioration, constituted a safety hazard and was aesthetically unpleasing.
 
C. Fissures and Deformations in the Vaults. Fissures and deformations in the vaults were revealed beneath the layer of imitation stone. The origin of these phenomena is related to the later construction above the vaults. The load that was generated, along with the percolation problem, caused cracks and distortions in the vault structure.
 
In 2006 a physical survey was conducted at the site by E. Cohen, a conservation engineer. He determined that the level of danger in the hall where the Temple Mount model is situated was high and required immediate intervention.
 
Conservation Measures in the Hall
The conservation measures implemented in the northern vault served as a model according to which all parts of the hall were treated.  The intervention included:
1. Removing the layer of imitation stone from prior intervention.
2. Installing temporary supports if necessary.
3. Removing plaster from the previous interventions.
4. Cleaning the joints.
5. Documenting the structure manually and by means of a laser scan.
6. Stone conservation.
7. Pointing up the joints with lime-based mortar.
8. Testing for voids by drilling.
9. Filling interior cavities (grouting) by injecting mortar into the core of the wall/vault.

 
Non-invasive means involving acoustic, optical and electromagnetic methods were utilized in order to estimate the size of the cavities above the vaults. These methods proved to be unreliable when compared with another test point in the Western Wall tunnel complex. It was therefore decided to perform further inspections by means of a series of drillings, which gave an indication as to the depth of the cavities, their size and location in the hall.
 
A critical deformation was discovered when conservation measures were begun in the center of the hall where the Temple Mount model is situated. One could easily see that the outer layer of the western vault had detached from its core and settled. A comprehensive survey of the internal area above the vaults in the hall indicated numerous cavities, some of which were large.  Dr. M. Ben-Bassat of the Department of Civil Engineering of the Technion in Haifa was consulted regarding these cavities and the deformation in the western vault. Dr. Ben-Bassat advised that microsilica be added to the mixture used to fill the voids above the vaults. Microsilica would speed up the drying time of the mixture and contribute to the strength of the material. The composition of the material was examined by the Isotope Institute which confirmed that the material was in keeping with the required standards. This is the first time filler material with a microsilica additive has been used in conservation measures in the country. Most of the ingredients in the fill were the same as those of the structure’s original mortar and they contain no cement. Mortar was injected into almost every part of the hall.
 
It was evident that the original building stones were missing in the vicinity of the deformation in the western vault. Loose stones in the vault had been removed, apparently in an earlier intervention, and were replaced with poured concrete. This concrete was dismantled in stages and new material that included microsilica was cast in building molds.
 
In conclusion, the measures that were carried out in the hall with the Temple Mount model provide a response to most of the problems that were apparent in that hall. The hazards that were present there were removed; the problems involving sewage percolation were partially solved and will only be completed alleviated when comprehensive intervention is implemented on the upper level; the conservation measures revealed and accentuated the original Mamluk construction technology of the hall; the hall was open to visitors during all stages of the treatment, while ensuring their safety; new fill material and castings, which are in keeping with the nature of the hall’s original mortar and fill, with a microsilica additive were utilized in the hall.

The future physical condition of the hall will depend on routine monitoring and maintenance.
....................................
Amit Rosenblum
January 2010


To view the figures, click on the figure caption
1. Plan of the hall with the Temple Mount model.

2. The hall with the Temple Mount model, looking northeast, before conservation measures were begun.

3. View of the bottom level of the hall with the Temple Mount model, at the time when it was used to prepare mortar.

4. The eastern vault upon completion of the conservation measures, looking toward the Western Wall and the “Master Course”.

5. Injecting mortar into the western vault.

6. Chart with the results of the test drillings in the northern vault.

7. Pipes used to inject mortar in the northeastern corner of the hall, arranged in the test drilling network.

8. Pipes used to inject mortar in the northwestern corner of the hall.

9. Section documenting the detachment of stones in the western vault (draftsman: ‘Attoun Hader).

10. Eastern part of the hall with the Temple Mount model upon completion of the conservation work.

11. Center of the hall with the Temple Mount model during the implementation of conservation measures there.

12.The center of the vaults after the completion of the conservation work.


Additional Projects
 Derekh Hebron - Conservation of the aqueduct to ancient Jerusalem
 The Western Wall, The Machkame Building - Conservation of the Southern Facade of the Machkema Building
 City of David - Conservation measures accompanying an excavation in the north of the City of David
 City of David - Conservation of the Shiloah Pool and preparing it for the public
 The Western Wall Tunnel - Conservation Report for 2005
 The Western Wall Tunnels, The Hasmonean Room - Conservation Treatment of the Hasmonean Room
 The Western Wall Tunnels, The Miqve’ot (ritual baths) - An excavation accompanied by conservation, conservation of the miqve’ot
 City of David, Givati Car Park - Stabilization and post-excavation conservation
 The Old City, Western Wall Tunnels - The Rabbi Getz Synagogue, Conservation and renewal
 The Western Wall Tunnels, The Secret Passage - Conservation and stabilization after excavation
 Zahal Square - Implementation of conservation measures
 The Old City - Conservation of the western ritual bath (miqve) in the Western Wall tunnel
 The Old City - Conserving the Engineers’ Tombs in the Jaffa Gate Plaza
 The Western Wall Tunnels, The Hasmonean Aqueduct - Conservation Measures for Removing Hazards
 The Old City - Conservation of the Church of St. Mary of the Knights (The German Church)
 The Western Wall - Hazard Removal
 Jerusalem - Maintaining Antiquities Sites in the Western Part of the City
 City of David - Conservation Maintenance
 The Wall Builders Garden - Conservation Measures
 Akeldama - The Conservation of a Crusader Burial Structure
 Ophel City Walls - Conservation of the Walls
 The Wall Builders Garden - Conservation and Development
 Mount Zion - Conservation Measures at David’s Tomb
 The Old City - A Plaster 'Pilot' Project in the Crusader Cardo
 The Ades Synagogue - Conservation of the Murals, 2013
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