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Construction Techniques
The walls at the site are quite massive and usually double battered. Most walls are about 90-100 cm thick near ground level, and taper to 65-70cm at a height of 4-5 m. The site boundary wall was 180 cm thick, and the niched halls have walls 120-150 cm thick. The walls are built predominantly of quarried sandstone. The unshaped sandstone blocks are laid up in a thick (3-6 cm) bed of mud mortar made from the local clay. The hearting consists of a compact but unorganized jumble of sandstone and mud. The size of stone varies greatly, but large blocks are rare and stones are typically 20-30 cm on a side. Snecks or chinking stones are common between larger stones in the face of a wall. Wall faces are usually relatively even, but stones in the wall face have no particular orientation. The lack of orientation of the facing stones gives a distinctive random appearance to the wall face which is typical of Huari constructions everywhere. In contrast, local Huamachuco architecture is faced with large rectangular blocks of stone completely surrounded by two to Five rows of smaller chinking stones, and has a coursed or semi-coursed appearance.
In all excavated examples, walls were started below ground surface in trenches as much as 3 m deep (for example, at the south gate), but generally these trenches appear to be only 1-2 m deep. The excavation of the trenches probably provided material for mortar and some fill for the preliminary leveling of the site. The foundation trenches were only as wide as the wall to be built and had vertical side walls. The construction of the wall inside the trench is as above, except that less care was taken in facing the below-ground segment of the wall. Again, this construction in deep trenches seems typical of Huari architecture; in contrast, Huamachuco buildings are always set directly on bedrock, and the bedrock is often cut away somewhat to provide a smooth footing for the wall.
The walls were built upwards in stages, as indicated by seam lines that usually run horizontally or obliquely horizontal. At times, more than one horizontal segment was built inside the trench. Generally, the height of the horizontal segment varies between 1 and 1.5 m, and the seam lines extend at times to more than 3o m in length. Short vertical seams sometimes subdivide a horizontal segment into two or more units. Horizontal segmentation is again typical of Huari architecture, while Huamachuco architecture emphasizes vertical segmentation.
The segmentation undoubtedly allowed more men to work simultaneously on the wall or building. Work crews might have had about five men, one to mix mortar, two to hand up materials, and two to lay stones simultaneously on both sides of the wall. It would be possible to have three or four crews at work on a single gallery wall. In such a situation, horizontal segmentation, as opposed to construction in vertical segments, would also serve the purpose of helping to level walls across a large area. Horizontal segmentation might also be related to the use of scaffolding. In this case, horizontal seams would result from increments in the number of levels of scaffolding. Since, however, the seams occur below ground level as well as above, it seems more likely that it relates primarily to leveling. In Unit A, for example, the variation from level of a row of corbels 50 m long was less than ± 5 cm, and these corbels occurred in two perpendicular galleries so that leveling could not be accomplished by simple line of sight.
Corbels (stones set into the wall and projecting out beyond the face) were used to support the floors of second stories. At Viracochapampa these stones were sometimes quarried but were more commonly river rolled. Sandstone, which is too friable, was rarely used for corbels; limestone or quartzite is preferred for this purpose. Corbels average 13 cm thick by 24 cm wide and protrude 18 cm from the wall face. On average they are spaced 11 cm apart. Sometimes a ledge, formed by thinning the second-story wall, was used as a floor support instead of corbels. Corbels and ledges always have a row of small niches immediately above them. These niches were probably designed to receive one end of a beam, while the other end rested on the corbels. They are about 25 cm high, 22 cm wide, and 27 cm deep.
While similar corbel (or ledge) and niche floor support systems were used at other Huari sites, I have the impression that they were not as standardized or evolved as those at Viracochapampa. Anders (this volume) comments that the corbels at Azangaro were made of rock too friable to support much weight, while at Pikillacta (McEwan, this volume) rows of corbels zigzagged and curved along the wall face. As mentioned above, at Viracochapampa the corbels were made of tough river-rolled rocks, a practice also found at Cerro Sazon, and were placed in nearly horizontal rows that were only occasionally stepped down to accommodate changes in the natural ground slope, a practice paralleled at both Marca Huamachuco and Cerro Sazon. It is most likely that the more standardized and evolved corbel-and-niche technique at Viracochapampa is due to the fact that similar supports had long been used in the local Huamachuco architecture.
The earliest examples of corbels at both Marca Huamachuco and Cerro Sazon date to around A.D. 400, and at that time they were used to support roofing beams. Later they were used to support the floor joists of multistoried buildings, and at Marca Huamachuco they were sometimes combined with holes in the wall. There are examples from this period of buildings with corbels on one wall with a row of holes on the other wall, as well as buildings with corbels on both walls with holes immediately above the corbels on either one or both walls. These holes were always dug into the wall after the wall was constructed, while the corbels were always built into the wall during the construction. It is obvious that one end of the joist was inserted into the hole, since we still find the ends of beams in the holes, while the other end rested on the corbels. It seems then that more corbels were built into the walls than were actually necessary to support the floor joists, since the spacing of holes and, therefore, of joists was 1 to 2 m apart, while the spacing of corbels is only about 10 to 20 cm apart. At Viracochapampa, prepared niches take the place of the unprepared holes and, like the corbels, many more are built into the walls than were absolutely necessary. At both these sites, whenever floor support features were built into the walls during initial construction rather than knocked in after wall construction, many were superfluous. This similarity between the two sites, on a detailed level of architectural planning and construction organization, reflects the fact that both result from the same tradition.
The niches associated with corbels have sometimes been viewed as evidence for the use of scaffolding during construction. As noted above, the use of horizontal segments might also be viewed as evidence of scaffolding. I feel, however, that in neither case is the evidence very good. Horizontal segment seams occur at or below ground level where no scaffolding would be necessary. Holes do not occur in all monumental buildings at Marca Huamachuco, are not known at all at Cerro Sazon, and seem confined only to the end of the Early Intermediate Period. When holes or niches occur at any of the sites in Huamachuco, their location is consistently at the same level as corbels. At Marca Huamachuco and Cerro Sazon, the vertical spacing between rows of corbels, or a row of corbels and the top of the wall, varies between 2 and 6 m; the exterior faces of walls at these sites are often more than 9 m tall and have no evidence of holes, niches, or corbels. Tying in scaffolding to the wall at 2 m intervals would be prudent, while building scaffolding up 6 to 9 m between tie-ins would seem very imprudent indeed. Certainly holes, niches, or even corbels might have been used to tie in scaffolding, but the real question is whether scaffolding was used at all. If it were used, I would expect to find a much more frequent distribution of holes on both interior and exterior wall faces, and these holes would not have to be aligned with rows of corbels; they could, after all, be easily plastered over later. Something like the rosettes that McEwan describes at Pikillacta might be evidence for scaffolding if they are frequent, but I am unaware of similar features at any of the sites in Huamachuco. In short, I do not feel that we can yet answer the question of whether scaffolding was used.
Small niches, like those associated with corbels, had lintels and sometimes sills formed by a single stone. Larger lintels, like those of the large niches in the niched halls or of doorways and windows, were formed by a number of stones held in place only by mud mortar. These larger lintels had to be supported while the mortar dried. This temporary support took the form of a solid masonry wall. Thus, when building a doorway, for example, the work crew first built the sill, which consisted of a number of stones laid to provide a smooth upper face. The door jambs, again consisting of a number of stones, were then constructed upward, along with the rest of the wall, until lintel height was reached.
It is likely that the temporary support was constructed and removed in a series of definite stages. On top of the sill they laid in a bed of clay about 1 cm thick, then began to fill in the doorway with the temporary masonry wall. However, since the doorsills were almost always constructed below ground level in the trench, the masonry support was often initially built only to ground level. This left the doorway clear to allow access across the trench and also provided a temporary bridge across it. When the wall surrounding the doorway had been constructed to the height of the lintel, the temporary support wall inside the doorway was built up and continued right into the lintel. After the lintel had dried, the support would be removed entirely or at least down to ground level, leaving a smooth sill and jambs but a rough lintel. It has been possible to reconstruct this technique because we have many example of partially completed doors, including one in which the entire temporary support is still in place.
Large niches were built the same way, but the sides and backs of the niche, as well as the floor, were apparently, given a rough coat of mud plaster. In one niche we found:. textile impressions in the plaster on the back wall. In this case, the piece of cloth may have served as a marker, so that the niche would not be damaged by workmen tearing out the temporary support masonry. Again, the incomplete niches in Unit C confirm that this was in fact the method o constructing lintels.
Lintels constructed in this manner are very weak points in the structure. In Viracochapampa's niched halls alone there were more than 1,500 large niches, and all the lintels seem to have collapsed. This inherent weakness may explain why so few doors and large niches have been recognized at other Huari sites; it does not explain why this technique was used. Similar lintels were used, at least on some large niches, at Marca Huamachuco, but I would see these as resulting from Huari influence. Earlier niches and doorways at Marca Huamachuco usually have stone slabs as lintels, while later buildings use either poles, stone slabs, or both poles and slabs.
An interesting technical detail relates to the construction of canal openings through the walls. We found three such:; canal openings. All were apparently meant to be below the floor, but none had actually been connected to a canal. A': were built using kaolin clay as the mortar. These are the only places where we find kaolin mortar, and it was probably purposely used to better seal these canals.
Walls were bonded onto each other in a number of different ways. There is one example of a "long-and-short work" corner. This type of bond, typical of the local Huamachuco architectural tradition, provides a decorative external corner on a building. It is constructed using rectangular blocks of stone that are longer than normal. The long axis of the block is alternately oriented vertically and horizontally. At Viracochapampa this technique was also used in the jambs of the niches in Unit C, and at other sites in Huamachuco it is sometimes used to mark one vertical edge of each building segment. More common a Viracochapampa is the overlapping of horizontal segment· to create a "finger bond" or an actual interdigitation o: individual stones to provide a true bond. While the true bond is also used in the Huamachuco area, the finger bond appears limited to Viracochapampa.
All three of these indicate more or less contemporaneous construction of the bonded walls. A fourth technique indicates pre-planning for the bonding-in of a later wall. This technique involves first building one wall, but also providing a series of stones projecting in a vertical line on the wall face. Later a second wall is abutted onto the first and tied into the projecting stones. This technique is common in the local Huamachuco tradition, where it was used especially to tie together a series of vertical building segments. The vertical rows of corbels described by McEwan may serve a similar function.
Interestingly, we have not observed at Viracochapampa the use of organic materials to strengthen wall corners, a trait that occurs at least at Huari and Pikillacta (McEwan; Lumbreras 1974: I62). Wooden poles are sometimes incorporated into walls at Marca Huamachuco, and this seems to be a borrowing from Huari.
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