Patent Publication Number: US-2019170275-A1

Title: Precast segmented annular structure with structural joint

Description:
INCORPORATION BY REFERENCE TO PRIORITY APPLICATIONS 
     This application is a divisional of U.S. application Ser. No. 15/466,017, filed Mar. 22, 2017, which claims the benefit of priority under 35 U.S.C. § 119(e) of U.S. Provisional Application 62/314,003, filed Mar. 28, 2016, each of which is incorporated by reference herein in its entirety. Any and all applications for which a foreign or domestic priority claim is identified in the Application Data Sheet as filed with the present application are hereby incorporated by reference under 37 CFR 1.57. 
    
    
     BACKGROUND 
     Field 
     This disclosure relates to in-ground and above-ground annular structures, and, in particular, to annular structures assembled from one or more precast segments. 
     Description 
     Annular structures, such as cylindrical structures, are common in a variety of in-ground (for example, buried) and above-ground applications requiring a variety of diameters and heights. In smaller or less deeply buried applications, rectangular structures can serve. However, in larger and/or more deeply buried applications, annular or cylindrical structures can be structurally and economically beneficial. 
     SUMMARY 
     The embodiments disclosed herein each have several aspects no single one of which is solely responsible for the disclosure&#39;s desirable attributes. Without limiting the scope of this disclosure, its more prominent features will now be briefly discussed. After considering this discussion, and particularly after reading the section entitled “Detailed Description,” one will understand how the features of the embodiments described herein provide advantages over existing systems, devices, and methods for sorting items. 
     In a first aspect, a segment for an annular structure, such as a cylindrical structure, is disclosed. The segment includes an arcuate body extending between a first end and a second end, the arcuate body having an inside surface and an outside surface. The segment also includes a plurality of first interlocking portions, such as hairpin bars, extending from the first end of the arcuate body, and a plurality of second interlocking portions, such as hairpin bars, extending from the second end of the arcuate body. The first and second interlocking portions can be similar or identical. For example, each interlocking portion can comprise a first leg and a second leg partially embedded in the arcuate body and a connecting portion, such as a curved or straight portion, for example, connecting the first leg and the second leg, the connecting portion external to the arcuate body. The segment desirably also includes a flange proximal to each of the first end and the second end of the arcuate body. Each flange can include a first spacing portion that extends radially outward from the outside surface and a second extending portion that extends distally from the main body portion, such as circumferentially or tangentially from a distal end of the first spacing portion. In some embodiments, the segment is precast. In some embodiments, the segment comprises cement or concrete. In some embodiments, the annular structure is a cylindrical structure. In some embodiments, the annular structure is an underground structure. In some embodiments, the annular structure is a manhole. 
     In a second aspect, a segmented annular structure, such as a cylindrical structure, is disclosed. The segmented annular structure comprises a plurality of segments arranged to form a hollow annular body. The annular body can be substantially cylindrical. Each segment can include an arcuate body extending between a first end and a second end, the body having an inside surface and an outside surface. Each segment includes a plurality of first interlocking portions, such as hairpin bars, extending from the first end of the arcuate body and a plurality of second interlocking portions, such as hairpin bars, extending from the second end of the arcuate body. The first and second interlocking portions can be similar or identical. For example, each interlocking portion can comprise a first leg and a second leg partially embedded in the arcuate body and a connecting portion, such as a curved or straight portion, for example, connecting the first leg and the second leg, the connecting portion external to the arcuate body. Each segment can also include flange proximal to the first end and the second end of the arcuate body Each flange can include a first spacing portion that extends radially outward from the outside surface and a second extending portion that extends distally from the main body portion, such as circumferentially or tangentially from a distal end of the first spacing portion. Joints between adjacent segments of the annular structure include overlapping the first interlocking portion of one of the plurality of segments with the second interlocking portion of another of the plurality of segments. Each joint can also include a field closure casting over the overlap of the first interlocking portion and the second interlocking portion. The field closure casting can comprise cement. The field closure casting can comprise rebar. The rebar can be inserted into the overlap of the first interlocking portion and the second interlocking portion. The field closure can be internal; in other words, made from an interior side of the annular structure. In some embodiments, each joint is transfers moments and shear forces between adjacent segments. In some embodiments, the annular structure is a cylindrical structure. In some embodiments, the annular structure is an underground structure. In some embodiments, the annular structure is a manhole. In some embodiments, each segment is a precast structure. The precast structure can comprise cement. 
     In a third aspect, a method for forming a joint between adjacent segments in an annular structure is disclosed. The joint is capable of transferring moments and shear forces between adjacent segments. The method includes overlapping interlocking portions, such as hair pin bars, extending from a free ends of a first segment with interlocking portions, such as hair pin bars, extending from a second segment. For example, each interlocking portion can comprise a first leg and a second leg partially embedded in the arcuate body and a connecting portion, such as a curved or straight portion, for example, connecting the first leg and the second leg, the connecting portion portion external to the arcuate body. The method also includes casting a field closure over the overlapping interlocking portions. In some embodiments, the method includes inserting a support member into the overlap between the interlocking portions. In some embodiments, the support member comprises rebar. In some embodiments, the field closure comprises cement or concrete. In some embodiments, the field closure comprises casting the field closure from an interior side of the annular structure. In some embodiments, the method further includes positioning a first segment relative to a second segment to form a section of the annular structure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The features and advantages of the present disclosure will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. These drawings depict only several embodiments in accordance with the disclosure and are not to be considered limiting of its scope. In the drawings, similar reference numbers or symbols typically identify similar components, unless context dictates otherwise. The drawings may not be to scale. 
         FIG. 1  is a perspective view of an embodiment of an assembled annular structure that includes a base, three segmented sections, and a cover. 
         FIG. 2  is an exploded perspective view of an embodiment of an annular structure including a base, a single segmented section, and a cover. 
         FIG. 3A  is a plan view of an embodiment of a segment of an annular structure. 
         FIG. 3B  is an interior side view of the segment of  FIG. 3A . 
         FIG. 3C  is a cross-sectional view of the segment of  FIG. 3B . 
         FIG. 4  is a plan view of an embodiment of a section of an annular structure formed from two segments, such as the half segment of  FIGS. 3A-3C . 
         FIG. 5  is a detailed plan view of an embodiment a joint between the two segments of  FIG. 4 . 
         FIG. 6  is a plan view of an embodiment of a section of an annular structure formed from three segments. 
         FIG. 7  is a plan view of the section of the annular structure of  FIG. 6 , which illustrates how the final segment can be rotated into place. 
     
    
    
     DETAILED DESCRIPTION 
     This disclosure describes annular structures made from one or more segments, as well as joints between the one or more segments that are capable of transferring linear forces (e.g., shear forces) and moments between the segments and around the structures. The term “annular structure” is to be construed broadly and includes, for example, cylindrical structures, round structures, and structures having curved portions. An annular structure can be a cast structure, such as, a structure cast from cement, concrete, or other materials. Annular structures can be used in a variety of in-ground (e.g., buried) or above-ground applications. As one non-limiting example, an annular structure can be a manhole. 
     The size of an annular structure can vary as desired depending on the application. For example, an annular structure can have an interior diameter of one foot or less ranging up to hundreds of feet or more. Annular structures with interior diameters larger than 12 feet, however, can often be difficult and expensive to transport. Thus, large annular structures are generally either cast in place (e.g., at the installation site) or assembled from one or more precast segments, which are cast offsite, transported to the installation site, and assembled to form the annular structure. In many situations, casting an annular structure in place can be undesirable, requiring, for example, extended periods of shoring around the installation site, dewatering, traffic control, and/or street or site closure. Use of precast segments can reduce or eliminate the disadvantages associated with cast-in-place annular structures, but can also introduces structural weaknesses into the annular structure as the joints between the segments create weaknesses in the structures. As will be described below, the precast annular structures described herein include joints which mitigate or eliminate these weaknesses. 
     Buried annular structures typically experience radial or axial forces imposed by the earth backfill surrounding the structure. Generally, forces exerted by the earth backfill do not impose a moment or shear force within the structure. However, live loads (for example, due to heavy passing trucks, etc.) can impose non-radial forces in the form of a uniform pressure on one side of the structure which creates a resulting uniform pressure on the opposite side of the structure caused by the earth backfill&#39;s resistive passive pressure. These uniform, non-radial live loads introduce both moments and shears into the buried annular structure. The magnitude of these forces can vary, for example, from 80 pounds per square foot (for an H-10 truck, for example) to as much as 2000 to 5000 pounds per square foot (for heavy mining haul trucks, railroads, or heavy aircraft). Above-ground (i.e., non-buried) structures can also be exposed to moments and shear forces due to seismic activity, wind, or other conditions. 
     The annular structures described herein can be constructed or assembled from one or more segments, and the joints between the one or more segments can be configured to transfer moments and shear forces continuously around the structures. Thus, in some embodiments, the annular structures described herein can provide the advantages associated with precast segments, such as increased portability and decreased installation time, while also providing the structural advantages typically associated with single-piece annular structures, such as the ability to transfer moments and shear forces continuously around the structures. 
     In the following detailed description, reference is made to the accompanying drawings. In the drawings, similar symbols typically identify similar components, unless context dictates otherwise. Thus, in some embodiments, part numbers can be used for similar components in multiple figures, or part numbers can vary from figure to figure. The illustrative embodiments described herein are not meant to be limiting. Other embodiments can be utilized, and other changes can be made, without departing from the spirit or scope of the subject matter presented. It will be readily understood that the aspects of the present disclosure and illustrated in the figures, can be arranged, substituted, combined, and designed in a wide variety of different configurations by a person of ordinary skill in the art, all of which are made part of this disclosure. 
     Reference in the specification to “one embodiment,” “an embodiment,” or “in some embodiments” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. Moreover, the appearance of these or similar phrases throughout the specification does not necessarily all refer to the same embodiment, nor are separate or alternative embodiments necessarily mutually exclusive. Various features are described herein which can be exhibited by some embodiments and not by others. Similarly, various requirements are described which can be requirements for some embodiments but cannot be requirements for other embodiments. 
       FIG. 1  is a perspective view of an embodiment of an assembled annular structure  100 . In the illustrated embodiment, the annular structure  100  includes a cover  110 , a body  120 , and a base  130 . The body  120  comprises three stacked, segmented sections  121 ,  123 ,  125 . However, greater or fewer numbers of sections can be stacked to form the annular structure  100  in other embodiments. For example, annular structure  100  can include one, two, three four, five, six, seven, eight, nine, ten, or more sections. As used herein, a “section” refers to an annular (e.g., circular or cylindrical) portion of the annular structure and that may formed as a single piece or from a plurality of segments. In some embodiments, the height of the annular structure  100  can be varied according to the number of sections used. For example, a taller annular structure  100  can include more sections than a shorter annular structure  100 , although this need not always be the case. 
     In the illustrated embodiment, each section comprises two segments. As used herein, a “segment” refers to an in individual piece that forms part of a section. A plurality of segments can form a section. For example, the section  121  comprises a first segment  121   a  and a second segment  121   b,  the section  123  comprises a first segment  123   a  and a second segment  123   b,  and the section  125  comprises a first segment  125   a  and a second segment  125   b.  In some embodiments, each section can comprise more than two segments, for example, three, four, five or more segments. In some embodiments, larger diameter sections may include more segments. Each segment can be configured for easy transport, for example, having a width of less than twelve feet. An example of a section comprising three segments is shown in  FIGS. 6 and 7 . In each section, the segments are attached to each other at a joint  140 . As will be described in greater detail below, the joint  140  is configured to transfer both moments and shear forces across the joint. 
     The body  120  of the annular structure  100  can comprise a hollow cylindrical (or other annular) shape with a substantially circular cross-section. Thus, each of the segments (for example, segment  121   a,    121   b,    123   a,  etc.) comprises an arcuate body, that, when joined with the other segments in a section (for example, section  121 ,  123 , etc.) forms the cylindrical body  120 . As noted previously, the height of the annular structure  100  can be adjusted by adding or removing sections. For example, a taller annular structure can comprise greater than three sections and a smaller annular structure can comprise fewer than three sections, in some embodiments. 
     In the illustrated embodiment, the body  120  is capped on one or both of the top and bottom ends by the cover  110  and the base  130 ; although, either one or both of the cover  110  or the base  130  can be omitted in some embodiments. That is, in some embodiments, the top and/or bottom of the body  120  can remain open. In the illustrated embodiment, the cover  110  comprises a substantially circular shape made up of three pieces  111 ,  113 ,  115 . The diameter of the cover  110  can be substantially the same as the diameter of the body  120 . Each piece  111 ,  113 ,  115  is joined to its adjacent pieces at a joint  117 . Each piece  111 ,  113 ,  115  can include a complimentary structure that mates with a corresponding structure on the adjacent piece. For example, the pieces  113 ,  115  include features to form a tongue-in-groove joint  117 . In some embodiments, the cover  110  can comprise a single piece, or greater or fewer numbers of pieces than shown in the illustrated embodiment. In the illustrated embodiment, the base  130  comprises two pieces  131 ,  133 . The base  130  can comprise a substantially circular shape. The diameter of the base  130  can be larger than the diameter of the body  120 . In some embodiments, the diameter of the base  130  is approximately the same as the diameter of the body  120 . In the illustrated embodiment, the pieces  131 ,  133  are joined at a joint  137 , which can be similarly formed to as the joint  117 , described above. 
     In some embodiments, the segments (e.g.,  121   a,    121   b,    123   a,    123   b,  etc.) of the annular structure  100  can be precast. That is, the components of the annular structure  100  can be precast at a manufacturing location, transported to a final destination, and then assembled to form the annular structure  100 . In some embodiments, the precast segments are made from concrete, cement, or other materials. The precast segments can be reinforced, for example, by including rebar (or other strengthening inserts, frames, or structures) structures embedded in the material from which the segments are cast. In some embodiments, strengthen structures may be attached to the exterior surfaces of the segments. 
     As noted above, it can be desirable that the annular structure  100  is configured to transfer moments and shear forces across the joints  140  between segments. 
       FIG. 2  is an exploded perspective view of an embodiment of an annular structure  100  including a cover  110 , a body  120 , and a base  130 . In the embodiment of  FIG. 2 , the body  120  of the annular structure  100  comprises only a single section  121 , which includes two segments  121   a,    121   b.  The cover  110  of the embodiment of the annular structure  100  of  FIG. 2  comprises two pieces  111 ,  113 . In other respects, the annular structure  100  shown in  FIG. 2  can be substantially similar to the annular structure  100  shown in  FIG. 1  and described above. In the exploded view of  FIG. 2 , the joint  140  is illustrated in greater detail. Each of the free ends of the segments  121   a,    121   b  includes a plurality of interlocking portions  150  extending therefrom. The interlocking portions  150  can be formed as, for example, hairpin bars. The interlocking portions  150  can be formed as overlapping portions. That is, when assembled, the interlocking portions  150  of the segment  121   a  can overlap and intermesh (with or without contacting) the interlocking portions  150  of the segment  121   b.  Stated another way, in some embodiments, each of the interlocking portions  150  of the segment  121   a  is positioned at a different vertical height than each of the interlocking portions  150 , such that when assembled, the interlocking portions  150  overlap each other. The interlocking portions  150  can be formed from rebar. The interlocking portions  150  are described in greater detail below. 
       FIG. 3A  is a plan view of one embodiment of a half segment  121   a  of an annular structure  100 . The half segment  121   a  can be configured to be joined to a second half segment to form a section of the annular structure  100 . The segment  121   a  illustrated in  FIG. 3A  and described in detail below can be representative of any of the segments of the body  120  of the annular structures  100  described throughout this application. The segment  121   a  comprises an arcuate body  205 . The arcuate body  205  includes an inner surface  206  and an outer surface  207 . The inner surface  206  can have a first radius. The outer surface  207  can have a second radius, the second radius being larger than the first radius. The first radius can be the radius of the inside of the annular structure  100  when assembled and the second radium can be the radius of the outside of the annular structure  100  when assembled. In some embodiments, the first radius of the inner surface  206  is 2 feet, 4 feet, 6 feet, 8 feet, 10 feet, 12 feet, 14 feet, 16 feet, 18 feet, 20 feet, 22 feet, 24 feet, 26 feet, 28 feet, 30 feet, 32 feet or larger; at least 2 feet, at least 4 feet, at least 6 feet, at least 8 feet, at least 10 feet, at least 12 feet, at least 14 feet, at least 16 feet, at least 18 feet, at least 20 feet, at least 22 feet, at least 24 feet, at least 26 feet, at least 28 feet, at least 30 feet, or at least 32 feet; less than 2 feet, less than 4 feet, less than 6 feet, less than 8 feet, less than 10 feet, less than 12 feet, less than 14 feet, less than 16 feet, less than 18 feet, less than 20 feet, less than 22 feet, less than 24 feet, less than 26 feet, less than 28 feet, less than 30 feet, or less than 32 feet or larger, or any value or range of values between the listed values. The second radius of the outer surface  207  can be larger than the first radius by 2 inches, 4 inches, 6 inches, 8 inches, 10 inches, 12 inches, 14 inches, 16 inches, 18 inches, 20 inches, 22 inches, 24 inches or more; at least 2 inches, at least 4 inches, at least 6 inches, at least 8 inches, at least 10 inches, at least 12 inches, at least 14 inches, at least 16 inches, at least 18 inches, at least 20 inches, at least 22 inches, or at least 24 inches; less than 2 inches, less than 4 inches, less than 6 inches, less than 8 inches, less than 10 inches, less than 12 inches, less than 14 inches, less than 16 inches, less than 18 inches, less than 20 inches, less than 22 inches, or less than 24 inches; or any value or range of values between the listed values, for example. The inner surface  206  can be substantially parallel to the outer surface  207 . The arcuate body  205  extends between two free ends  211 . The free ends  211  can be substantially planar surfaces extending between the inner surface  206  and the outer surface  207 . In some embodiments, the free ends  211  can have a non-planar profile. 
     In the illustrated embodiment, support members  202 ,  204  are embedded in the arcuate body  205 . In some embodiments, the support members  202 ,  204  comprise rebar embedded in the arcuate body  205 . In the illustrated embodiment, support members  202  are embedded in the arcuate body  205  every  6  inches along the height of the arcuate body  205 . The support members  202  are embedded between the inner surface  205  and the outer surface  207  and are curved to follow the shape of the arcuate body. The support members  202  can be parallel to the top and or bottom surfaces  208 ,  209  of the arcuate body shown in  FIG. 3B . The support members  202  can be embedded every 2 inches, 4 inches, 6 inches, 8 inches, 10 inches, 12 inches, 14 inches, 16 inches, 18 inches, 20 inches, 22 inches, 24 inches or more, for example. In some embodiments, the support members  202  can be omitted. In the illustrated embodiment, support members  204  are embedded in the arcuate body  205  every  12  inches along the length of the arcuate body  205 . The support members  204  are embedded between the inner surface  205  and the outer surface  207 . The support members  204  can be parallel to the free ends  211  of the arcuate body  205 . The support members  204  can be embedded every 2 inches, 4 inches, 6 inches, 8 inches, 10 inches, 12 inches, 14 inches, 16 inches, 18 inches, 20 inches, 22 inches, 24 inches or more, for example. In some embodiments, the support members  204  can be omitted. In some embodiments, support members  204  a perpendicular to support members  202 . 
     In the illustrated embodiment, flanges  220  extend from the outer surface  207  of the arcuate body  205  proximal to the free ends  211 . In the illustrated embodiment, the flanges  220  include a first spacing portion  221  that extends generally radially outward from the outer surface  207  proximal to the free ends  211 . The flanges  220  also include a second extending portion  223  that extends distally from the arcuate body  205 , such as circumferentially or tangentially from the end of the first portion spacing  221 . 
     In the illustrated embodiment, the arcuate body  205  and the flanges  220  are integrally formed. The arcuate body  205  and the flanges  220  can be formed (e.g., cast) from concrete, cement, or other materials. In some embodiments, the arcuate body  205  and the flanges  220  are cast at the same time. The material can be reinforced throughout with support members (such as support members  202 ,  204 ). As shown in the illustrated embodiment, the arcuate body  205  is reinforced with both tangentially support members  202  and longitudinally extending support members  204 . A support member  206  also reinforces the flanges  220  and can extend from the arcuate body  205  into the flanges  220 . 
     The interlocking portions  150  extend tangentially outward from the free ends  211 . As shown in the side view of  FIG. 3B , in the illustrated embodiment, the interlocking portions  150  comprise hairpin bars that extend outwardly from the free ends  211  approximately every six inches along the height of the segment  121   a,  although other spacings of smaller or greater distances are possible. For example, the interlocking portions can be spaced every 2 inches, 4 inches, 6 inches, 8 inches, 10 inches, 12 inches, 14 inches, 16 inches, 18 inches, for example. Further, as shown in  FIG. 3B , the interlocking portions  150  extending from one free end  211  are offset from the interlocking portions  150  extending from the other free end  211 . That is, the interlocking portion  150  on one free end are positioned at different vertical heights than the interlocking portions  150  on the other free end  211 . This can allow the interlocking portions  150  to overlap with or intermesh with (with or without contacting) the interlocking portions of another section to form a joint  140  as described herein. Accordingly, the interlocking portions  150  can be considered overlapping portions. For example, on the free end  211  illustrated on the left side of  FIG. 3B , the first interlocking portion  150  is spaced a distance D 1  from the bottom edge  209  and subsequent interlocking portions  150  are spaced each spaced a distance D 3  up the free end  211 . On the free end  211  on the right side of  FIG. 3B , the first interlocking portions  150  is spaced a distance D 2  inches above the bottom edge  209  and subsequent interlocking portions  150  are each spaced a distance D 3  up the free end  211 . The distance D 1  can be different from the distance D 2  such that the interlocking portions  150  on one free end  211  are offset or staggered relative to the interlocking portions  150  on the other free end  211 . The spacing between interlocking portions (D 3 ) can be the same on each free end  211 . 
     For example, the distance D 1  can be 3.5 inches, the distance D 2  can be 6.5 inches, and the distance D 3  can be 6 inches. Thus, in this example, the interlocking portions  150  on the left free end  211  are offset from the interlocking portions  150  on the right free end  211  by approximately  3  inches. As will be described below, when two segments  121   a  are joined together, the interlocking segments  150  of one segment overlap with the interlocking segments  150  of the other segment. In this example, there would be a three-inch spacing between interlocking portions  150  from each segment  121   a.  These dimensions are provided by way of example, and other spacings and dimensions are possible. The interlocking portions  150  can be considered overlapping portions because the interlocking portions  150  overlap with the interlocking portions  150  of an adjacent segment  121   a  when installed. 
     Returning to the illustrated embodiment of  FIG. 3A , the interlocking portions  150  are each formed as a hairpin bar includes first and second legs  151 ,  152  that are connected by a connecting potion  153 . In some embodiments, the connecting portion  153  can be curved or straight. In some embodiments, the legs  151 ,  152  extend into the arcuate body  205 . The legs  151 ,  152  can be slightly curved so as to follow the curvature of the arcuate body  205 . In some embodiments, the distance between the legs  151 ,  152  is substantially constant. In some embodiments, the interlocking portion  150  can be a substantially U-shaped hairpin bar, although, as noted above, the free ends of the U can follow the curve of the arcuate body  205 . In some embodiments, the interlocking portions  150  each lie substantially in a plane that is parallel to a plane containing the top edge  208  or the bottom edge  209  of the arcuate body  205 . Or, stated another way, in some embodiments, the interlocking portions  150  each lie substantially in a plane that is normal to the longitudinal axis of the segment  121   a,  body  120 , or annular structure  100 . 
     A cross-sectional view of the segment  121   a  is shown in  FIG. 3C . As shown, the upper edge  208  can contain a lip  208   a  and the lower edge  209  can contain a lip  209   a.  The lips  208   a,    209   a  can facilitate stacking of the sections  121 . Accordingly, the lip  209   a  can have a complimentary shape to the lip  208   a.  The profile of the upper edge  208 , lip  208   a,  lower edge  209 , and lip  209   a  can be varied in a wide variety of ways, all of which are within the scope of this disclosure. 
       FIG. 4  shows a plan view of one embodiment of a section  121  of an annular structure  100  formed from two segments  121   a,    121   b.  As shown in  FIG. 4 , in the assembled state, two segments  121   a,    121   b  are brought together to form the section  121 . The segment  121   a  is positioned such that the second portions  223   a  of the flanges  220   a  are brought into contact with the second portions  223   b  of the flanges  220   b  of the segment  121   b.  In this position, the interlocking portions  150  extending from the segments  121   a,    121   b  overlap in a void  141  created between the free ends  211   a,    211   b  and the flanges  220   a,    220   b  of the segments  121   a,    121   b.    
       FIG. 5  shows a detailed view of one of the joints  140  between segments  121   a,    121   b  of  FIG. 4 . The joint  140  is formed by overlapping the interlocking portions  150  in the void  141  formed between the free ends  211   a,    211   b,  and the flanges  220   a,    220   b.  As noted above, the interlocking portions  150  of the free end  211   a  of the segment  121   a  can be offset from the interlocking portions  150  of the free end  211   b  of the segment  121   b.  Thus, when viewed from above as in  FIG. 5 , the interlocking portions  150  of the segments  121   a,    121   b  overlap and can be considered overlapping portions. The joint  140  can also include support members  208  positioned inside or outside of the connecting portions  153  of the interlocking portions  150 . In some embodiments, the support members  208  comprise rebar. In some embodiments, the support members  208  can be attached (e.g., tied, welded, etc.) to the interlocking portions  150 . 
     The joint  140  also includes an interior field closure casting  142  in the void  141 . The interior field closure casting  142  can be formed when the annular structure  100  is assembled by filling the void  141  with concrete. Importantly, because the flanges  220   a,    220   b  shield the void  141  from the excavation, long term shoring is not necessary, and the interior filed closure casting  142  can be made from the interior of the annular structure  100 . The assembled joint  140 , as shown in  FIG. 5 , is capable of transferring moments and shear forces across adjacent segments of the annular structure  100 . 
       FIG. 6  shows a plan view of one embodiment of a section  121  of an annular structure  100  formed from three segments  121   a,    121   b,    121   c.  A joint  140  is formed between each of the segments  121   a,    121   b,    121   c  as described above. The joint  140  is configured to transfer moments and forces across the joint  140  between the segments  121   a,    121   b,    121   c.    FIG. 7  is a plan view of the section  121  of the annular structure  100  shown in  FIG. 6 , which illustrates how the final segment  121   a  can be rotated into place. The annular structure  100  and segments  121   a,    121   b,    121   c  shown in  FIGS. 6 and 7  can be substantially similar to the annular structures and segments discussed above. However, this embodiment includes three segments for each section instead of two. Similarly, the number of segments can be varied to include even greater numbers of segments, such as, four, five, or more segments. Increasing the number of segments in a section can allow construction of annular structures with increasingly larger internal radii, while still allowing for individual segment sizes that are easily transportable. The joints  140  between segments  121   a,    121   b,    121   c  can be formed as described above in reference to  FIG. 5 . In some embodiments, the section  121  can comprise other numbers of segments, for example, two, three, four, five, six, seven, eight, nine, ten, or more segments. 
     The foregoing description details certain embodiments of the systems, devices, and methods disclosed herein. It will be appreciated, however, that no matter how detailed the foregoing appears in text, the systems, devices, and methods can be practiced in many ways. As is also stated above, it should be noted that the use of particular terminology when describing certain features or aspects of the invention should not be taken to imply that the terminology is being re-defined herein to be restricted to including any specific characteristics of the features or aspects of the technology with which that terminology is associated. 
     It will be appreciated by those skilled in the art that various modifications and changes can be made without departing from the scope of the described technology. Such modifications and changes are intended to fall within the scope of the embodiments. It will also be appreciated by those of skill in the art that parts included in one embodiment are interchangeable with other embodiments; one or more parts from a depicted embodiment can be included with other depicted embodiments in any combination. For example, any of the various components described herein and/or depicted in the Figures can be combined, interchanged or excluded from other embodiments. 
     With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations can be expressly set forth herein for sake of clarity. 
     It will be understood by those within the art that, in general, terms used herein are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims can contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to embodiments containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B.” 
     All references cited herein are incorporated herein by reference in their entirety. To the extent publications and patents or patent applications incorporated by reference contradict the disclosure contained in the specification, the specification is intended to supersede and/or take precedence over any such contradictory material. 
     The term “comprising” as used herein is synonymous with “including,” “containing,” or “characterized by,” and is inclusive or open-ended and does not exclude additional, unrecited elements or method steps. 
     Reference in the specification to “one embodiment,” “an embodiment,” or “in some embodiments” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment described in the disclosure. Moreover, the appearance of these or similar phrases throughout the specification does not necessarily refer to the same embodiment, nor are separate or alternative embodiments necessarily mutually exclusive. Various features are described herein which can be exhibited by some embodiments and not by others. Similarly, various requirements are described which can be requirements for some embodiments but are not requirements for other embodiments. 
     The above description discloses several methods and materials of the present invention. This invention is susceptible to modifications in the methods and materials, as well as alterations in the fabrication methods and equipment. Such modifications will become apparent to those skilled in the art from a consideration of this disclosure or practice of the invention disclosed herein. Consequently, it is not intended that this invention be limited to the specific embodiments disclosed herein, but that it cover all modifications and alternatives coming within the true scope and spirit of the invention as embodied in the attached claims. Applicant reserves the right to submit claims directed to combinations and sub-combinations of the disclosed inventions that are believed to be novel and non-obvious. Inventions embodied in other combinations and sub-combinations of features, functions, elements and/or properties can be claimed through amendment of those claims or presentation of new claims in the present application or in a related application. Such amended or new claims, whether they are directed to the same invention or a different invention and whether they are different, broader, narrower or equal in scope to the original claims, are to be considered within the subject matter of the inventions described herein.