Contributed by barbara-dave
Description: February 27, 1892 Post Office Page 16Date: February 27 1892
Newspaper published in: Washington, D. C.
The Evening Star February 27, 1892 Post Office Page 16
THE POST OFFICE SITE.
The Borings Compketed and Rock Found at Every Point Tested.
The borings on the site of the new city post office have been completed for the present, and until the return of Architect EDBROOKE from Chicago there will be no more probings into the earth. The results of this work have been a surprise to all and extremely gratifying to everybody connected with the construction of the building. Rock has been encountered under the surface at depths varying from twenty-five feet eight inches to thirty-eight feet half an inch. The average depth of all the eight borings that have been made is thirty-one feet ten inches.
The first four holes were bored in the corners and the next series of four in the middle of the sides, somewhat further from the edges than those on the corners, so that there were a great variety of panes developed. The general dip is unmistakably toward the north, contrary to all expectations. The rule seems to be reversed for in the average geology the dip is toward a stream, and the presence of the Potomac would surely be a reason to look for a slope in the rock bed to the south. Instead of this the southern edge of the bed is about eight feet nearer the surface than the northern edge.
The bottom of the bed is at an unknown depth, as no borings have yer been made into the rock to determine its thickness. In one of the pits the drill was sent down seven inches into the rock, and in another place the work was stopped about five inches after rock was encountered. It may be that when Mr. EDBROOKE has examined the results he will order that two or three borings be continued so as to determine as far as possible the thickness of the stratum of rock. If it should be no more than eight inches thick it will be amply sufficient for all purposes, as the main desideratum is a firm bottom for the piling that will undoubtedly be driven to support the foundation. It is not thought that it will be at all practicable to excavate the lot all the way to the rock, as there would be unusual difficulties in the way. The cost of excavation, too, is such that the final expense of digging out the lot would not fall far short of the cost of piling.
There are materials in plaes throughout the square, before the rock is encountered, through which it will be extremely difficult to drive piles. Some of the gravel is so compact that the drill could scarcely be forced down, and there is one pocket of sand that the borer calls “hard pan” in one of the shafts that was so tenacious that he was half an hour penetrating eleven inches. Thus he says will surely resist a pile and he thinks that an ample foundation will be found before the rock is touched. It is his individual opinion that there is sufficient bottom in the lot to support a ten-story building without any piling.
The rain of the present week has sadly interfered with Contractor GLEASON's plan of getting his excavation completed next week. He has been working hard to turn the lot over to the government in half the time that he agreed to occupy. His contract expires April 1, and he has estimated that without any interference from Jupiter PLUVIUS he would have completed every stroke of work on the square by next Wednesday, or in just half the time specified. This would have been a wonderful record for this time of the year, but even as it is there will be time saved, and it would appear as though the lot would be ready for the foundation work long before the architect has made his arrangements for a contract.