|
| Site Dewatering | Lateral Earth Support System | Effect of Pumping on Groundwater Levels | ||||||
|---|---|---|---|---|---|---|---|---|---|
Construction Project | Location | Years of Dewatering | Probable Lowest Elevation | Method or Remark | Type | Lowest Stratum Penetrated | Distance from Excavation | Drawdown | Other Remarks |
| Sewers & Drains | |||||||||
| West Side Interceptor | Charles St. to Beacon to Hereford to Falmouth to Gainsborough St | 1877-1884 | Varied el. -2.0 to el. -7.5 | Underdrains & sumps | Probably wood sheeting | Organic Silt & Sand | No records available | Significant drawdown in adjacent areas probably occurred. See Figure 4. | |
| Low Level Sewers | Throughout Back Bay | 1910-1912 | Underdrains & sumps | No records available | Significant drawdown in adjacent areas probably occurred. | ||||
| West Side Interceptor Relocation | At Christian Science Church Center | 1968-1969 | el. -7.5 | Wellpoints in sand | Steel sheet piles | Clay | 100 ft. 700 ft. 100 ft. | 8 to 10 ft. in Sand none in Sand 3 ft. in Fill | Recharge around Christian Science Church eliminated drawdown in Fill. |
| Subways | |||||||||
| Boylston Street Subway | Boylston St. from Arlington St. to beyond Mass. Ave. | 1912-1914 | el. -19.0 | Deepest between Arlington St. & Copley Square | Steel sheet pile | Clay | No reports available | Siphon pipes installed to allow groundwater movement across structure. See Table 2. | |
| Huntington Avenue Subway | Beneath Exeter St. & Huntington Ave to beyond Mass. Ave. | 1937-1940 | el. -20.0 | Lowest under Mass. Turnpike & railroad | Steel sheet piles | Clay | 200 ft. 800 ft. 1100 ft. 0.4 mi. | 13 ft. in Sand 12 ft. (after 2 yrs.) 8 ft. in Sand 7 ft. in Sand | Dewatered for 3 yrs. WPA data indicated large area affected (Mass. Ave. to Dartmouth St.). See Table 3. |
| Huntington Avenue Subway Prudential Entrance | near West Newton St. | 1969-1970 | el. -15.0 | Steel sheet piles | 300 ft. 400 ft. 800 ft. 1000 ft. 1200 ft. 1400 ft. | 18 ft. in Sand 4 ft. in Sand 6 ft. in Sand 8 ft. in Sand 6 ft. in Sand 4 ft. in Sand | Dewatering for 5 months. No drawdown observed in Fill. | ||
| Southwest Corridor Project | Mass. Ave. to Harcourt St. Harcourt St. to Berkeley St. | 1981-1985 | el. -15.0 to el. -28.0 | None required Sumps in excavation | Concrete diaphragm walls Sheet piles, soldier beams & lagging | Top of Clay Organic Silt | None observed that was attributable to corridor tunnel construction. | Excavation open 1-2 yrs. Observ. wells at each street. See Table 4. Rises to el. -4.0 east of Dartmouth St. | |
| Buildings | |||||||||
| Christian Science Publ. House | Norway St. | 1931-1934 | el. -3.0 to el. -6.0 | Wellpoints in Sand | Unknown | Sand | 300 ft. 300 ft. 1000 ft. | 8 ft. in Sand 2.5 ft. in Fill 4-5 ft. (in Sand?) | |
| New England Mutual Life Ins. Co. Bldg. | Clarendon St. between Newbury & Berkeley Sts. | 1939-1940 | el. -21.0 | Sumps in excavation | Soldier piles & lagging | Clay | Nearby | 4-6 ft. in Fill | No Sand at site. |
| John Hancock Berkeley Bldg. | Berkeley St. between St. James & Stuart Sts. | 1946-1947 | el. -25.0 | Sumps in excavation | Soldier piles & lagging | 90 ft. 140 ft. | 10 ft. 7 ft. in Fill | No Sand at site. | |
| Boston Herald Traveler Bldg. | Harrison Ave. between Herald & Traveler Sts. | 1957 | Deep in sand above bedrock | Unknown | 1 mi. | 30 ft. in deep sand | Dewatering for caissons to rock. | ||
| Christian Science Publ. House Underground Equip. Rm. | Norway St. adjacent to Mother Church | 1958 | el. -3.0 | Wellpoints in Sand | Steel sheet piles | Sand, halfway through | At excavation 500 ft. 1200 ft. | 11 ft. in Sand 8 ft. in Sand 4 ft. in Sand | Little drawdown in Fill. |
| Prudential Center Tower | Center of Prudential Center Complex | 1959-1960 | el. -12.0 | Wellpoints in Sand | Steel sheet piles | Clay | Nearby | 16 ft. in Sand 1-2 ft. in Fill | Recharged Fill & Sand outside sheeting. |
| Sheraton Hotel at Prudential Center | Dalton & Belvidere Sts. | 1962-1963 | el. -4.0 | Wellpoints in Sand | Steel sheet piles | Clay | 400 ft. | Initially, 3.5 ft. in Sand | Recharge system correction eliminated drawdown. |
| 180 Beacon St. Apart. Bldg. | Beacon & Clarendon Sts. | 1964-1966 | el. -14.0 | Unknown | Concrete slurry walls | Unknown | Nearby | 12-15 ft. in Sand | Slurry wall leaked. Recharged Sand outwash unsuccessful. |
| Christian Science Admin. Bldg. | Huntington Ave. between Belvidere & Cumberland Sts. | 1967-1968 | el. -5.0 | Open pumping in excavation | Unknown | 200 ft. 500 ft. | "Some" in Fill 0 ft. in Fill | ||
| Christian Science Colonnade Bldg. | Clearway & Belvidere Sts. | 1968-1969 | el. 0.0 | Shallow, probably by sumps | Unknown | "Minor" in Fill | No data available on off-site drawdown. | ||
| John Hancock Tower | Clarendon, between St. James & Stuart Sts. | 1968-1974 | el. -28.0 | Sumps within site | Steel sheet piles | Clay | Near | Negligible in Fill | No Sand at site. |
| Christian Science Church New Portico | West Side of Mother Church | 1973 | el. -4.0 | Wellpoints in Sand | Partially sheeted | Sand | 40 ft. 90 ft. 230 ft. | 8 ft. in Sand 4.5 ft. in Sand 5.5 ft. in Sand | No drawdown observed in Fill. |
| Symphony Plaza Apartments | Mass. Ave. at St. Botolph St. | 1977 | el. +4.0 to el. -3.0 | Sumps in pile cap pits | Unknown | Nearby | 3 ft. in Fill | ||
| Greenhouse Apartments | Huntington Ave. at W. Newton St. | 1981 | el. -2.0 | Sumps in pile cap & elevator pits | Soldier pile & lagging | Organic Silt | 40 ft. | 3 ft. in Fill | |
| Copley Place | Huntington Ave between Harcourt & Dartmouth Sts. | 1981-1982 | el. -4.0 | Sumps in pile cap excavations | Soldier pile & lagging | Organic Silt | Near | Minor in Fill | Only pile cap excavations went below groundwater. |
| One Exeter Place | Boylston & Exeter Sts. | 1982-1983 | el. 0.0 | Sumps in excavation | Steel sheet piles | Clay | Nearby | Negligible in Fill | |