WiredTiger:error (-31802)

I am attempting to repair a corrupted db, but --repair doesn't work. I have also tried salvage with the wt tool. These are the errors:

[1570846069:870738][86561:0x7f6d231e0740], file:WiredTiger.wt, WT_CURSOR.next: read checksum error for 16384B block at offset 86016: calculated block checksum of 1998645344 doesn't match expected checksum of 1386055393
[1570846069:870765][86561:0x7f6d231e0740], file:WiredTiger.wt, WT_CURSOR.next: WiredTiger.wt: encountered an illegal file format or internal value
[1570846069:870771][86561:0x7f6d231e0740], file:WiredTiger.wt, WT_CURSOR.next: the process must exit and restart: WT_PANIC: WiredTiger library panic
[1570846069:870784][86561:0x7f6d231e0740], txn-recover: Recovery failed: WT_PANIC: WiredTiger library panic
lt-wt: WT_PANIC: WiredTiger library panic

I have attached WiredTiger.wt and WiredTiger.turtle. Any help would be appreciated.

Thanks,
Qicai