US1638473A - Sewer construction - Google Patents

Description

1,638,473 Auf@ 9s 927- v, H. cocHRANE SEWER CONSTRUCTION Filed Jun@ 18, `1925 v2 sheets-sheet 1 EE- EJB r' 3' j "."ill 1' 3 ,//l 1g. E1- Mmm a@ l l S? s a www@ l l 1,638,473 Aug' 9 1927' v. H. cocHRANE SEWER CONSTRUCTION Filed June 18, 1925 Y 2 Sheets-Sheet 2 61H01 nuja Patented Aug. 9, 1927.

UNITED sTATEs VICTOR E.' OOCHRANE, OF TULSA., OXLAHOIL SEWER CONSTRUCTION.

Application mea .rune is, ma. smal m. sam-s.

This invention relates to improvements in sewer constructions.

The primary object of this invention is the provision of a sewer construction, whereby the stresses upon the sewer may be accurately determined.

A further object of this invention is the provision of an improved sewer construction embodying novel means of forming the arch upon the abutment, with hinge joints, so as to do away with uncertain stresses in monolithic construction. A

A further object of this invention is the provision of a sewer construction which will materially reduce the quantity of concrete required with certain types of sewer constructions, such as the monolithic construction, and provide in addition a sewer in which the stresses can be foreseen and safely taken care of.

A further object of the invention is the provision of a sewer construction including abutments and -an invert independently connected by means of flexible joints, so that the invert is prevented from carrying any part of the load from the arch or abutments, and further providing an arch section attached to abutments by means of joints which are so constructed as to fix the location of the resultant thrust at the center of the arch section at the joint, so that the arch is vir` tually two-hinged for dead load and fixed or partially fixed for live load.

A further object of this invention is to provide a sewer construction which includes the formation of the abutments, upon which the arch barrel is subsequently supported by means of novel joint constructions which permit hinge action of the arch upon the abutments, thus enabling the arch barrel to adjust itself to the pressure exerted by the filling material thereover, and to the shortening of the axis caused by the compressive stresses.

Other objects and advantages of this invention will be apparent during the course of the following detailed description.

In the accompanying drawings, forming a part of this specification, and wherein similar reference characters designate corresponding parts throughout the severalv views.

Figure 1 1s a cross sectional view taken through the completely constructed sewer, at a typical cross section, and showing the comparative formation of the same with the another ste present requirement of monolithic structure of the same size; the monolithic structure being shown in this view in dot and dash lines.

Figure 2 is a fragmentary sectional view taken on a horizontal plane substantially on the line 2 2 of Fi re 1.

Figure 3 is a sectional view taken through an abutment of the sewer construction, showing the rst step in the formation of the sewer construction.

Figure 4 is a fragmentary sectional view showing the form work at the joint between the arch at its springing edge and the abutment.

Figure 5 i's a sectional view showing in the construction of the arch upon the a utment, by means of which the same has a hinge action thereon during the filling of earth or other material over the arch to permit the arch to settle and adjust itself to the pressure of the .dead load.

Fi re 6 is a fragmentary sectional view showing an alternative 'form of joint construction.

In the drawings, wherein for the purpose of illustration is shown only a preferred construction of the arch and a preferred design of the same, the letter A may generally designate the finished sewer construction, which may consist of the abutments B; arch C, and invert D.

In present types of sewer constructions, the stresses may bemaccurately figured only in case the foundations are firm and unyielding, whereas if there should be any settlement or rotation of the arch abutment at its foundation unforeseen stresses may be set up throughout the arch ring. Some sewer constructions to obviate this require the sewer invert, archesf and abutments to be made very thick, in a monolithic construction. This is so especially in-the case of sewers resting up'on soft foundations, in contradistinction to rock foundations. To obviate this factor by increasing the thicknesses of the parts of the sewer is sometimes inconvenient and expensive. To do away with lsuch uncertainty of stresses, the novel sewer construction and method of forming the same herewith set forth has been provided, which will enable all stresses'to be accurately determined, and requires the use of only about the same amount of material for a soft foundation, as would be necessary for a rock foundation of present sewer constructions. lt is extremely economical as compared with `forms of sewer construction now in use. ln Figure 1 has been given the comparative sizes of sewer constructions according to my method and according to a present known method, in which the latter is illustrated in dot and dash lines.

Prior to the forming oit the arch portion C, the abutment-s B and relerably the invert l) are constructed. lie abutments B are formed to provide the mein body portion 10, which provides an inside wall surface 11 adapted to lie contiguous with the intrados 12a o the arch C. it the out-er side of the body of the abutment B, the abutment extension 12 is provided, oit any approved length, providing a toot for distribution of load thrust; the heifrht ci this extension 'l2 between the top suriace 18 oit the abutment and the bottom surface 1li thereof, preierably decreasing towards the outer edge of the extension 12. As a novel feature ezt the abutment B the same is provided with an invert extension portion 15, providing a toe, so 'to speak, for the abutment B, which extends at the opposite side or the abutment from the extension 12, and which in reality is a part of the invert oi the sewer A. This toe or invert extension 15 is of course considerebly reduced in height with respect to the ebutment, and it has a top surface 18 to lie contiguous with the invert iiotv surface and provide part of the same.

The reinforcing oit the abutment B plays important part in the sewer construction, and during the formation or the abutment, the reinforcing rods or bars 20 and 21 are embedded in the cementitious material of the abutment. @The rods 20 and 2f. are crossed at 2d, and preferably held by a ring 25 or analogous element at this point just upwardly of the top surface 13 of the abutment E, and which cross location 24 really lies in the joint space 26 when the arch C is connested to the abutment i3, as has been illustrated in Figure 5 oi the drawings. rThe bars 2O and 21 from the cross location 24 extend upwardly in divergent relation, and provide the end portions 28 and 29 adapted to be embedded in the springing portions or' the arch C to hingedly connect the arch to the abutments. The reinforcing bars or rods 20 and 21 extend into the abutment B preferably in divergent relation, at portions 30 and 31, and the portion 3.0 may terminate at 32, or it may be arcuated and bent lor embedding at la portion 3d extending into the invert or toe extension 18, for reinforcing the same. Additional reinforcinof rods may also be provided along the bottom of the abutment throughout the Width thereof, as has been illustrated in the drawings.

inasmuch as the reinforcing bars or rods 20 and 21 are in compression, it may be advisible to insert stirrups, ties or thrust disneed-17s tributing lates 39 land 40 in the abtments B and arc C, adjacent the joint space 26, to prevent cracking of the concrete or cementitious material.

The invert D is separated from. the inver extensions 15 of the abutments B, by means oli joints t5, which may be any approved flexible or sli construction joint, such as tar paper, or ot er elastic substance such as asphalt, resting directly on the foundation or held in. place by stirrups 46, which at their ends are anchored in the invert and abutment, as is illustrated in Figures 1 and 5 of the drawings. l't is to be particularly noted that with such a construction the main invert D does not comprise the entire invert, but the extension 15 may also be considered as included in the term invert. lll/'ith this construction the joints are placed much closer to thecenter line of the sewer, than are invert joints which have heretofore been provided in sewer constructions of proportionate size. With such construction the invert E is made relatively shallow, since it does not support any of the dead load thrusts, and the abutments may move relative thereto Without racturing the invert main section D,

filter the abutments have been placed, the joint space 26 is filled preferably with some suitable material that can be removed to permit arch settlement, such as forms made up 01E detachable wedge pieces 50 and 51. The inner and outer i'orms of the arch C are of course placed, and the reinforcement 53 and 54C adjacent the intrados and entrados sides of the arch are placed, and the concrete is poured and allowed to set in the form provided therelor. After the arch concrete has been sufficiently cured, the forms are removed and the earth or other covering over the arch is placed. l1 wooden :forms have been used in the joint space 26 they are removed either before or after the dead load has been placed, and at this juncture the entire weight of the arch and su erposed loads will be concentrated upon t e cross locations 24 of the reinforcing rods 2O and 21, at the center of the joint space 26, and as can be readily understood, thus denitely fixing the location of the resultant thrust at these points. After the arch has had time to adjust itself, and the earth lill and the foundations have fully settled, the joint space 26 may be pointed up with any suitable filling material 56, which may be cement or some elastic material, such as asphalt. In lieu of using the wooden forms and 5l to support the arch during its formation, the spaces 26 between the abutments and the arch springing ends might belled with some elastic substance, as asphalt, which will remain permanently in place. This construction is preferable in the event that it is imprac` ticable to place the full amount of earth filllil@ lil)

ing on the arch at the time of construction, in which case the layer of elastic material is made as thin as may be, and at the same time to permit of a suicient amount of rotation of the arch relative to the abutment. To prevent access of water to the reinforcing rods 2O and 21, longitudinally extending metal diaphragms 61 and 62'may be used, at opposite sides of the hinge joints provided by the crossing `of said rods, said diaphragms being embedded in both the abutment and arch ring, and providing, in effect, aclosed channel, as is illustrated in Figure 6 vof the drawings.

As to the steps of construction, the preferred method of forming the sewer is to first form the abutments B and the invert D, and the arch barrel C is subsequently supported in the manner above described upon the hinges formed by the reinforcing rods 2O and 21, orin any other analogous manner which will permit a slight rotational movement at the ends of the arch. The joint spaces are then filled with cement, concrete or other suitable material, such as elasticv asphalt, although not until the sewer trench has been back filled and the filling material allowed to settle, andthe arch to adjust itself to consequent pressures. If such adjustment cannot be accomplished at the time of construction, the joint filling material to be of an elastic nature and left in place, being formed on the abutments B. before the arch C is built. It is also contemplated to provide other hinge connections not shown specifically by the reinforcing bars 2() and 21.

The advantages of the above method consist essentially in the fixing of the position of the line of thrust at the center of the arch section and concentrating it at joints adjacent to the arch support upon the abutments, so as to permit some relative movement between the arch barrel and abutments, without fracturing the sewer construction, as does actually occur in monolithic sewer construction. It is a fact that with this im- .proved method of sewer construction, the

arch and abutments can be made lighter in section and with smaller quantities of reinforcing steel than other sewer constructions of the same size, thus effecting a considerable economy without any decrease in strength.

Thus, briefly, it can be seen that the sewer construction consists of a pair of abutments at each side, an invert 'section separated by joints from the abutments permitting relative movement so that the abutments may settle independently of each other and the invert, and preventing the invert from carrying part of the load of the arch and abutments; and lastly an arch section attached to the abutments by means of hinge joints which fix the location of the resultant thrust at a place which can receive the same with- 'fixed for live loads.

out fracturin any part of the sewer construction. T e arch is thus virtually two hinged for dead load and fixed or partially An additional advantage 4is that the improved sewer construction reduces the stresses caused by the arch shortening, so called, as compared with the ordinary monolithic construction.

Various changes in the steps to place the various parts of the sewer construction, shape, size, and arrangement of parts may be made to the invention herein shown, illustrated and described, without departing from the spirit of the invention or the scope of the claims.

I claim:

1. In a sewer construction the combination of abutments having integral invert extensions, a main invert section, means flexibly connecting the main invert section at its ends with said invert extensions of said abutments, and an arch superposed upon said abutments.

2. In a sewer construction the combination of abutments having integral invert extensions, a main invert section, means flexibly connecting the main invert section at its ends with said invert extensions of said abutments, an arch barrel, and yieldable joint means connecting the arch barrel at its springing ends in a leak-proof connection upon said abutments for limited relative movement with respect to said abutments.

3. In a sewer construction the -combination of abutments, an arch, reinforcing members embedded in said abutments and in said arch to hingedly connect the arch to said abutments, and diaphragm members longitudinally extending along said abutments and arch embedded therein at opposite sides of each of the joint connections provided by said reinforcing members.

4. In a joint construction a pair of concrete sections, metal reinforcing members each embedded in each of said sections and extending across the joint location between said sections, and flexible metal diaphragm means embedded in each of the sections at each side of the location where the said reinforcing members cross the joint between said sections, to seal the joint location agiinst access of moisture to said reinforcing ro s.

5. In a exible joint construction the combination of a pair of concrete sections, reinforcing rods embedded in each of the sections and extending across the location be tween said sections whereby to hingedly connect the sections together to permit relative movement thereof, and a metal diaphragm member at each side of the location where the reinforcing rods cross the joint location of said sections, each metal diaphragm member being embedded in each offthe sections and crossing the joint location between said sections to liquid seal the rods at the joint location against access by moisture.

6. lin dexible joint construction the combination of e pair of concrete sec-v tions, reinforcing rods embedded in each oi the sections and extending across the .locetion between seid sections whereby to bingedly connect the sections together to permit relative movement thereof` a metal pbregrn member et each side of the location where the reinforcing rods cross the joint location oi said sections, each metal din bregni member being embedded in each o' tbe sections end crossing the joint location between said sections to liquid seal the rods at the joint location against access by moisture, said dexible diapbragms at the crit location being crimped to facilitate the timing tbereo during relative movement of concrete sections.

L lin n i'dexible joint construction the coinbinetion of e pair of concrete sections, reiniorcing rods embedded in each ot the secg tions and extending across the location between seid sections whereby to bingedly connect the sections together to permit relative movement tbereoii, a metal diaphragm niember et eacli side of the location where the reinforcing rods cross tbe joint location ot said sections, eacb inetel diaphragm member being embedded in eecii mi the sections and crossing the joint location between said sections to liquid Seel 'tbe rods at the joint location egsinst eccess by moisture, and sealing; inateriei in tbe joint location between said concrete sections outwardly beyond said diapnregms;

8. In a sewer constriiction the combination of elon ated abutments each including a body portion and a reduced laterally er; tending invert extension of less height than the body ortion, an elongated invert between the invert extensions and in top surface iush relation therewith, exible joint means connecting and sealing tbe joints between the longitudinal edges of the invert and tbe invert extensions of said abutments, e. inain arch ring, and metal binge connections embedded in tbe ends ont the arch ring and the body portions of the abutments to inount tbe springing ends of tbe ercb ring for some relative movement with respect to the ebutinents.

9. in a sewer construction tbe combination ot' elongated abutments each including .e body portion and a reduced laterally extendinvert extension ot less height than the body portion, an elongated invert between the invert extensions end in top surface iinsb relation therewith, dexible :ioint means connecting and sealing tbe joints between the longitudinal edges of tbe invert end tbe invert extensions of seid abutments, e main eren ring, metal binge connections embedded in the ends of tbe eren ring end tbe body portions of the obntrnents to mount tbe springing ends olf. the arcb` ring for sonic relative movement with respect to tbe ibutinents, and an elastic non-concrete construction in the joint location between tbe springing ends ot the arch ring and tbe abutments :tor sealing end nrotecting the binge rods against deterioratinnf inuences.

vieron n. contienne.

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